Fuel Systems Masterclass - Profitable Diagnostic Solutions

hi electron John the driveability guy here with you we're continuing on with our educational Series today we're going to be talking about fuel systems so as you can see we got plenty of fuel system related stuff out on the table for us we also got a car behind us that we're going to attempt to do some live different types of testing um through some of the comments that I've read that I've been reading from the channel here as of late that you ask to see a little bit more Hands-On so I'm going to try to do as much Hands-On but we still have to have an understanding of what we're doing so I don't not sure how long this video is going to be we're we're going to give it a shot we're going to see if we if you guys don't mind watching a longer video you know we'll start incorporating more and more hands on stuff as we go through these continuing um educational series here so fuel systems we all know that fuel systems have evolved over the years we could go all the way back to carburation which I've got one or two little little quick little slides we're not going to spend pretty much any time on carburetors because if you're like me you probably haven't seen a carburetor come into your shop in decades so we'll start with the carburation we'll kind of tell you why we got away from carburetors and then we'll go right into fuel injection and how fuel injection has evolved over the years so what were the big problems with carburetors so the big problems with carburetors were they were mechanical by Nature so anything mechanical eventually is going to wear out over time so we'd have Sloppy linkages um it's also very temperamental for huge degrees of weather changes with the with the chokes on the vehicles and stuff and if they had a manual choke you know a lot of times customers would pull the choke and step on the gas pedal to start the car like they're supposed to but they'd forget to turn the choke all the way off you know so then you'd have filed out spark plugs and everything along those lines um mixture control devices once we came out with computer controls those weren't very sophisticated so in essence we're taking a a metering Rod out of a jet and it's a tapered metering Rod so the more we pulled it out the more fuel could go in one of the biggest problems with fuel that we need to understand is fuel has to be atomized so in order to atomize it you know with a carburetor we would step on a gas pedal or whatever accelerator pump would just dump a bunch of fuel inside the combustion chamber we needed to have heat to help the atomization proc process liquid fuel as you guys are well aware doesn't necessarily burn it's the it's the fumes that actually burn so you know they weren't very efficient overall and some of the problems that we talked about were if you think about that that actual intake manifold there we would get a puddle of fuel and if it was a V8 styled or six-cylinder or whatever style design wherever the fuel was at in the center of that intake manifold well those those cylinders would technically run richer were the outside outling type of cylinders that fuel would have to get sucked into each one of those intake Runners so those would always be a little bit on the leaner side so that was a balancing type of problem another big problem with those systems were a lot of times we would use a mechanical fuel pump and a mechanical fuel pump like this obviously is be being driven in some way shape or form off the cam shaft and it's a pretty strong diaphragm inside there with the spring on the mechanical arm over here so there was a lot more load being placed on the engine by having to drive this fuel pump modern day cars as you're well aware use an electric fuel pump so you know we don't really have that extra that extra drag on the engine which cleans up the emissions coming out of the tailpipe because they don't have to work as hard so before we get into fuel injection let's talk a little bit about Fuel and I'm going to just throw some random thoughts out there you know fuel is you know vitally important we used to have Leed gasoline now it's all unlet type of gasoline there's different octanes of fuel obviously there's different alcohol content in fuel as well everything from the winter blend gasolines which roughly has about 10% all the way up to E85 the latest and greatest so we're going to talk about fuel for a little bit here and a couple little cases and point if you ever pull up to a a service station or a gas station whatever you want to call it nowadays and you happen to see one of those tanker trucks there filling up the underground tanks probably not the best time for you to fill up your car now obviously if you need gas and there's no other fuel station in the vicinity you know anything goes at that point but if you think about it any type of contaminants that's in that tank in the ground when we're dumping in you know hundreds thousands of gallons of gas from a fuel tanker it's stirring up that so you'll have a tendency to want to you know possibly get some of that debris inside your fuel filter and restrict your fuel filter so it's better to not buy gas if possible when you see a fuel tanker truck there the difference between leted and unlet gasoline it's not a big concern of ours anymore but when they stop making leaded gasoline there's a lot of cars out there that still ran on leaded gasoline you know I have a classic 68 Camaro in the corner of my shop that car was originally designed to run on Leed gasoline so the extra lubricants that the leaded gasoline provided us we had to all of a sudden change the internal design of of the combustible engine there so that it could account for the fact that we don't longer have those extra lubricants inside there octane levels you know the higher the octane the the better the burn of inside that cylinder the more power it's going to create if you use nothing but premium ium gasoline maybe you took did a tuneup on a car in the past and you took the spark plugs out and you read the stories that the spark plugs tell you and you notice that the that the ceramic the ceramic material around the center electrode has like a reddish or a pinkish appearance well that's coming from the higher octane fuel that they're using so the problem is the alcohol there's there's advantages to using alcohol and Fuel and those advantages are number one alcohol doesn't freeze as as quickly as gasoline does so for fuel line freeze up which is why we put all across the nation during the winter months we're allowed to have up to you know roughly 10% of alcohol in the fuel here in the states um but once uh once a summertime Springtime comes out you know a lot of times we don't have that high of alcohol content anymore it also will burn cleaner than gasoline now why don't we want to have just alcohol inside there well alcohol reaks havoc on all the all your components in your fuel system it's harder on your fuel pump itself it's harder on any type of rubber type of lines that distribute the fuel from the back of the car to the front of the car there's a lot of disadvantages to the alcohol too the other thing too is alcohol burns at a faster rate so the anybody has a flex fueled vehicle which basically means it can run on regular gasoline or it can run on E85 gasoline E85 is cheaper when they fill up their tank but it doesn't last as long because it burns faster than the regular or unlet type of gasoline that we're accustomed to fill in here so with that being said those are some of the advantages and disadvantages of of the alcohol now you know if you wanted to ever do any type of fuel system test on your car here's a company it's called revx they make this nice little thing but you could pretty much use any type of clear container put some lines on it yourself and basically what you do is you fill it so much with water and then you put the rest of it up to the top line up with gasoline and then you let it sit totally still so it's going to it's moving around a little bit for me grabbing it off the other cart but over time you'll see how the the water and the gasoline and the alcohol kind of separate from one another and it floats on top of the water so this gives you kind of an idea of how much alcohol is in the the fuel content on your car plus it's see-through so if there was contaminants in the fuel you'd actually see debris laying in the bottom of it as well so where this becomes so important is you know a lot of the E85 type of cars that we have on the road today there's a sensor that's on the fuel rails that will always be able to determine how much alcohol contents in that tank of gas if you think about it let's say one time you fill it up with E85 but then afterwards you start putting you know conventional unlet gasoline in there well you no longer have 85% alcohol you have maybe you know a mixture of that some sort could be down to 40% or whatever depending on when you filled your tank up last well the car's computer always has to know what the alcohol content happens to be because if it doesn't it doesn't really know how to change the fuel delivery and Spark timing curves so that extra sensor is primarily just being used to determine how much alcohol contents in in the fu Fu system that the fuel system happens to be using at that time it's constantly being updated there's a lot of cars out there um some of the older cars that's in the late 90s early 2000s where those sensors would fail and when they would fail it could it could actually even uh cause a no start type of thing so that's like a little silver bullet I'll throw out there for you guys so that's something to keep in mind um this car is not E85 behind us so I can't show you that sensor with the scan tool or nothing but I wanted to make reference reference to that before we went too much further so you might be asking yourselves well what's the whole deal with the with the gasoline in the first place right if you ever had one of those oldfashioned lawnmower or any type of yard equipment gas cans you remember that it used to have a little vent on the back of it and the federal government got involved and to me I hate the fact that they got rid of that vent because it's a lot harder to get the gas out of there at this point because there's no air vent helping you you know spill the gas into the gas tank your snowblower lawnmower whatever the case happens to be but the reason why they did that is because gasoline in a sealed container has something that's called a reed vapor pressure and lots of things affect the Reed vapor pressure of gasoline alcohol has read vapor pressure values as well but one of the things is it's a sealed container temperature plays a big part that's why you may hear on a hot summer day on the radio they tell you hey it's an ozone alert day don't fill up your gas tank because basically we need someplace for those expanding hydrocarbons to go so if the gas tank was totally full with liquid there wouldn't be as much room for the for the extra fumes that's being created at that point also with that being said as far as a read vapor pressure goes this helps explain why over the years the car manufacturers there was a time when we used to just vent it right out to the atmosphere now we use an EVAP system and then we took it a step further and we did a returnless fuel system because also the flowing of that gasoline also has an effect on the Reed vapor pressure so instead of taking the gas from the gas tank sending it up to the engine more than what we needed and then returning it back to the gas tank what we did not need for that particular engine running cycle there that extra slashing of the fuel going back into the tank would have an effect on the re vapor pressure as well so that's why you know evap systems have evolved um in the very simple forms we'll eventually do a series on evap systems but in simple forms you know that's how an EVAP systems designed to work it's supposed to take those expanding fumes and instead of venting them to the atmosphere it stores them in a canister usually under the hood or under the car depending on the vehicle you're working on and then the next time you start the car up your purge solenoid will just open up and vacuum will suck those fumes out and you'll burn them through the active combustion of the engine and we don't necessarily really have too many vehicles out there that still use a return line on the fuel systems so that started back in the early 2000s so continuing on with fuel let's talk a little bit about fuel pumps so we have all different types of fuel pumps that are out there I showed you one already that's the old fashioned mechanical one that's a relatively low pressure then we got into what we call high pressure which were electric fuel pumps those could be found you know mounted to a frame rail on a car they could be found inside the gas tank whatever the case happens to be um but we no longer really call those the high pressure fuel pumps because we came out with something called gasoline direct injection which is really high pressure so before we were dealing with you know maybe 30 PSI up to say 60 PSI on average um nowadays with gasoline direct injection we'll still use that conventional style fuel pump what we call conventional nowadays but we call that the low pressure system where you know the true low pressure fuel pump was you know somewhere between 3 and 7 PSI for many many decades so a high-pressure fuel system you will use the low pressure pump to actually pump it up to the the fuel rail area but it goes through the high pressure pump which happens to be this guy here and that could take the pressure and go to several hundred PSI if not you know over a th000 PSI and this will be driven right off a camshaft lobe we'll be talking more about this as as we go through the the presentation here so we also came out with something that's called three-phase fuel pumps so I give Toyota credit for this I could be wrong on that but they were the first ones that I ever came across with it three-phase fuel pumps operate a little bit differently a conventional fuel pump you give it a power and a ground it would actually start to Pump Fuel however a three-phase fuel pump operates much like your alternator or your motor generators and an electric Drive type of vehicle whatever the case happen happens to be where we're pulsewidth modulating that signal so in order to test those you can't really just hook up your lab scope to it um you can't really just give it power or ground so you need some type of three-phase tester if you've been watching along with this series you know that a good buddy of mine Joe Casey Joe's Auto Electric actually makes a tester for that that you can then hook up to the car and then hook your scope up to it and or your multimeter whatever you're using to test it and you could get valid test results from it so the three-phase fuel pumps are relatively new more and more car lines have gone that way um like I said I give Toyota credit for being the first ones but don't quote me on that that's just the first car line that I saw using the three-phase fuel pumps now when we're talking fuel pumps so as before I go move on here here's an automotive fuel pump that would be part of the the uh actual sending unit inside the tank I obviously removed the fuel pump from it cut it apart so I can get uh the most important part of this out and here's the little Armature and you'll notice that this Armature has got a total of eight different segments on it so this is a a brush style setup so as this thing rotates this is what's creating what's called a fuel pump current waveform which has a lot of diagnostic information in it if you know how to acquire that waveform so as we continue on with the fuel pump testing any type of motor so a fuel pump is nothing more than essentially some type of little electric motor here modern day fuel pump so we got a couple ways that we could test it we can overall test the fuel pressure right that's a test that we've all done a million times we hook up a fuel pressure gauge to it some cars it's easier than others to actually hook up the fuel pressure gauge to it and we're going to get an overall pressure however if there's any type of restriction in the system that pressure is always going to want to read the same value right I used as in one of the previous videos you know putting your finger over the water hose as an example right so you're restricting the actual flow of water but the pressure actually increased there so that's where using a fuel pressure gauge kind of like this one becomes a lot more valuable for us because this type of fuel pressure gauge will not only read the pressure with the gauge up on top but it also has a flow meter and side of it now in order to use this tool I got to hook up to the to supply line the pressure line but I also have to have a return line hooked up and I'm actually not only reading the pressure but also reading the volume of fuel there now if you don't happen to have one of these fancy tools out there you can do the same thing with your conventional fuel pressure gauge by getting the actual pressure by reading off the gauge but they always have some type of bleed on them right so you could take this other hose from a conventional fuel press pressure gauge and you can just time so you push this button the car is still running at the time and you just go ahead and divert some of that fuel pressure into some type of clear clear bucket or a clear bottle of some sort you know and then you're going to measure you know after say 15 seconds or so how much fuel is actually filled up inside that that clear container there and that gives you a pretty good idea of what the actual flow is doesn't give you the exact idea like this the the this more fancy fuel pressure tester here is but you know a lot of cars don't have a return system on them anymore as we just stated so it becomes a little bit harder to make the hookup with this tool as opposed to Conventional fuel pressure gauge which is why you could revert back to what we used to use for years before a tool like this ever came out where we just used a clear cylinder of some sort to get an idea of what the flow was so a fuel pump before we continue to go on we don't send direct power and ground to it right because that's going to draw higher amperage and a car's computer is in control of allowing that fuel pump to turn on so any computer on a car can't handle more than about a 3/4 of an amp draw so we'll use a relay so there's going to be a fuel pump relay maybe if it's a modern day car it might be a fuel pump module driver module whatever the case happens to be so we're going to be using something that's going to take low current coming from an actual PCM on a car or ECM whatever you want to call it and be able to control a high amperage type of device such as a such as a fuel pump relays are used for that same purpose over and over again all throughout the car doesn't matter if it's cooling fan relays whatever the case happens to be so with that being said it's important to be able to test that circuit on a car which I'm going to show you how to do that here in a second second but if I use a low amp inductive current probe I'll get a fuel pump waveform now there's a lot of advantage to the fuel pump current waveform so number one we will see that hey on the the top picture being displayed on the screen you'll notice that what we're after is I call those camel humps we would like to see uniform camel humps for a good fuel pump right we got a couple dropouts there so when I look at that I know I can just count how many camel homps are between there and I know at that point how many commutators are on the fuel pump right so let's just say that there was eight I would know that there's eight because I in between each one of those times of dropping out there's seven other ones and then the Dropout one so if you've ever had any vehicle come into your shop for any type of motor whether it be a fuel pump whether it be a blower motor a wiper motor you know a cooling fan motor a starter motor at some point in our careers when we were relatively young and naive maybe we had a no start where it didn't crank and some oldtime you know seasoned veteran told us hey go underneath the car while I hold the key in the in the crank position and hit that starter motor with the hammer so basically what you did is you made a little bit of a vibration which allowed that commutate commutator to have a better contact with the brushes so any type of brush style motor is is subject to this type of failure so there's a fuel pump waveform that I have from a previous case study that I did over the years where the customer's complaint was they call you up and they say hey my car doesn't start so the car cranks and everything but there was no fuel pressure because where the last time it was shut off at was on one of those Dropout areas by the time the car came to my shop the car started up no problem right so again I'm always under the belief that the customer is not lying to us he's not just lonely he doesn't want to come visit me and makes up some erroneous problem so I got to take that type of complaint and I got to say well what could cause that from happening one of them being the fuel pump right another thing could be with the ignition systems not really in this video so I just went ahead and did a quick simple hookup with my low amp inductive probe when I saw that I knew that it was a fuel pump that was causing the problem the reason why it started when it came to my shop was because it tow truck jostled it around enough that we had better brush contact with those commutators there now if I know that how many commutators there are on that fuel pump I can also determine not only the overall amperage which would be the height of that waveform but the speed of that fuel pump so here's a little story that I can share with you guys you know I once worked at a shop where all the time I was being told to put a fuel filter on a car because it could be restricted and if you in the northern climate this the Rust Belt like I do you know and you have a screw on type of fuel filter like this guy a lot of times that's that's a big chore by itself trying to get those lines unscrewed without breaking the fuel lines so I came up with this idea and it's not a real you know Earth shattering idea but technically if this fuel pump is if this fuel filter I'm sorry is restricted two things are going to happen to that waveform number one it's trying to Pump Fuel but it's hitting a mechanical restriction inside here so now that fuel pressure is fighting to overcome that mechanical restriction and it backs up and when it starts to back up the rotational speed of the fuel pump actually slows down as a result of that also because it's trying to overcome a mechanical restriction the amperage is going to go higher right so this would require you knowing what known good values are for the speed and the amperage so a little bit of testing on your part you know on some known good cars much like a lot of the diagnostic tests we do requires but once you know what those are now you can say hey is this fuel filter actually restricted because the other way to test it would be to take it off the car and try to blow through it right and that's a lot more a lot more work involved as opposed to just you know clipping an inductive amp clamp around either the power ground fee to the fuel pump so I put a little thing up there that you guys have probably seen at this point that is telling you how to determine so if you know what your scope settings are and you can go ahead and determine how many commutators there are on the fuel pump you'll be able to do this same type of test you'll be able to tell the the overall RPM and amperage of that fuel pump now let's get back to what we were talking about with fuel pump relays and a fuel pump relay you know whether wherever the happens to be located you know so here's here's a Chrysler product I'm just holding this up as demonstration purposes here but here's an actual fuse and relay Center so let's pretend like it was you know this relay here which I don't know if this is the one or not but for sake of the video that's fine so if you ever look at a wiring schematic you know this is an ISO style relay the oldfashioned style where it basically has pin 30 and 87 and 85 and 86 but if on every relay there's always a little schematic and that little schematic always tells you what the switching one is right so the two that would close when the contact close that's going to send power back to whatever it's trying to to power up in this case we're using a fuel pump as an example so it's really easy to test These Guys these aren't very hard to test you know you could switch them out with another one that's right next to whatever the case happens to be but there's a lot of diagnostic value and saying hey is the circuit working right so if you test did this and this is good now if I go inside there and I jumper that switch circuit so in this case it happens to be 30 and 87 if I jumper those two that would be the same as if this relay closed inside there and whatever that is hooked to on the vehicle should start to activate so in this case it would be the fuel pump you should hear that turn on right so how do you test the circuit is a quick little thing because you're basically taking your Diagnostics and cutting it in half is it a problem with the wiring or the component or is it a problem with the switch side of the circuit so that's where you have all the different types of relay testers that are out on the market so you know over over the years these different types of um relay testing circuits have evolved so I could take something like this it's got a little onoff switch would be the same as you jumping those two terminals um it also has a an inductive amp wire going around it so I can take and put my inductive amp probe around there and get an amperage reading once I turn the thing so I love this this style because I don't have to sit there and babysitting and plus I can measure the amperage right there's also the style that AES wave produces this is called a new activate it comes with a whole bunch of different harnesses and stuff it's got all the different meter leads but notice it's got the inductive amp clamp loop around it as well so I can go ahead and do the same type of scenario as this kit of relays now my down my dislike of this kider relays is if you've been in the automotive industry for any length of time they keep changing the relay design right so you know this one has six different relays that came in the kit I like it but sometimes I go to take a relay out of a fuse block or or whatever wherever it's located and I'm like well it's it's a different design right it still operates the same way but it's a different design and I don't have something that's made to actually plug right into the thing and you activate does have more of a choice of the harnesses that it comes with to be able to to substitute that or you can do something that I did did this years ago after the frustration of them autom manufacturers keep changing the fuel pump relay designs or any type of relay design and I just made a universal relay tester right so you know I got a fuse protected if you don't want to have a fuse protected not a big deal I've got the amp loop on there obviously this button will turn the thing on and off but then I got just got two two leads coming out of it and these two leads here I can just go ahead and say okay no matter what type of relay it happens to be I look at those those closed contact part of the schematic on the relay and I just put these two leads in that in that scenario there now I can just go ahead and push a button right and hook up my amp clamp do all the testing and stuff so that's something you can make as well it's not that that difficult of a tool to actually make so the relays are important and if if I push the button on any one of these things or flip the switch or whatever the deal happens to be and the fuel pump order to start running I know that the problems with the switch side of the circuit if it doesn't run then it could be a harness problem going down to the device or it could be a faulty device like a bad fuel pump in this scenario all right so now let's continue back with fuel injection is how it's evolved over the years here and we came out next with something that was called a throttle body injection now the throttle body injection injection would have either one or two injectors right these injectors were usually low resistance style injectors and this was called a peak and hold style injector so what that basically meant was it was just constantly pulsing on and off over and over and over again and then as we open up the throttle plates whichever cylinders needed the fuel would it's just like the oldfashioned carburetor we just taking the atomized fuel at this point because an injector has got a very small opening from the pinle we're spraying it into the intake manifold and through vacuum we're sucking it into the cylinder who's got an open intake valve on it at that point as you can see it's still a mechanical style design so you still have that disadvantage like we had with carburetors and we're still relying on the puddling effect from the intake manifold so there were some disadvantages to the throttle body type of injection here but it was still way better than carburetors cuz we didn't have a choke any anymore the coolant temperature sensor acts as the choke on a modern day car um we also didn't have we didn't have to um rely on heat to help atomize the fuel because it's the the fine opening pretty much is creating atom atomization as it's being sprayed into the engine now that waveform a voltage waveform from that looks like what you see on your screen now where we basically are creating two types of voltage spikes so to measure that we would measure from when the voltage dropped down all the way over to the second Spike during that time is when we were charging the fuel injector and actually spraying Fuel and then obviously at the end of the second Spike we no longer we turned it off so why does it create a spike and you know what's going on with the with the voltage level being dropped and everything else I used this as an example in one of the earlier diagnostic videos but it's I use that garden hose as an example you've got a lot of water pressure pressure holding that squeeze type of garden hose closed right the pintle on that hose closed it takes an amount of force to overcome that water pressure holding that close so you got to squeeze it a little bit harder to get it to open up to overcome that pressure that's holding that pinol closed but once you've actually squeezed it and water starts coming out you don't have to squeeze it as hard anymore right you just got to barely kind of hold on to it to allow it to stay open so that's what we're seeing here through representation of using a scope that it took you know let's say three amps or so to overcome the fuel pressure that's holding the pinol on that injector closed but once it's open it doesn't take that many amps anymore to keep it open so that's why we had the two spikes there so those had problems too fuel injection was relatively new we could have you know shorted injectors and stuff over the time we've evolved and a lot of the common problems with fuel fuel injection has kind of Fallen by the wayside now the problem with that was it was it was way better than carburetors but we still it wasn't quite as good because we were still polluting the air greater than what we could do if we went to one injector for each cylinder so again this is all the evolution here so we came out with something called a multi-port fuel injector so we would have you know four injectors six injectors eight injectors how many cylinders were on a car and each one of these would each one of those cylinders would have an injector on it now we did not have camshaft position sensors back then so what this would do is this would spray the fuel two times per four stroke cycle not a big deal right is better than throttle body where we're just spraying like crazy once the intake valve opened up for that cylinder it would suck in both of those fuel sprays into the combustion chamber the disadvantage to this was well that puddling of fuel on a closed intake valve before it opens up for the second spray there well that develops a bunch of carbon so now carbon acts as a sponge so if I got fuel and I got a bunch of carbon inside of a cylinder whether it's on inside the cylinder on the backside of the intake valve whatever I'm spraying fuel in there but a lot of that fuel is being soaked up by the carbon which means that the cylinders would run a little bit lean we used to have to clean injectors all the time you know there was a lot of companies out there making injector cleaners at the time and um that was a big service that we would do that would cause the cars to run rough possibly misfire a whole host of driveability type of problems so that was the the port fuel injection now that type of waveform along with sequential fuel injection and other types of waveforms did away with the two Spike system that wasn't a saturated switch style type of injector anymore it was either on or off right so what we did here you can can see on your screen this is how we'd look at this type of waveform this is a voltage pattern again so we are requiring some amperage just like always to actually open up the injector but now when the injector turns off we only have the one Spike so once that injector turns off then we're just waiting for the next time for this it was told by the PCM to go ahead and fire these injectors again now we have something a better way to test fuel injectors so we got the voltage pattern it's important for all us to understand what those voltage patterns are relating to us because if I had a voltage pattern and I had a shorted injector well the voltage spike is going to be different than from what a known good injector pattern would look like and stuff but we're only seeing when the computer tells it to turn on and when the computer tells it to turn off when we're looking at a voltage pattern but we know that even though we're ramping up current inside there to overcome that fuel pressure holding the pinol shut it doesn't actually open until there's enough current to overcome that that holding of pressure there so we have something called a pental hump and that's when it's actually opening there's current is high enough inside this injector now to actually overcome that fuel pressure that's being sent to the top of the injector and now it opens up and fuel starts to spray out of the bottom of it so that's known as a Pinal hump so if I use a low amp inductive probe I can see that when that Pinal hump actually starts spraying fuel so even though we're charging that coil of windings inside that injector for a longer period of time we're not actually spraying fuel until that until we see that pental hump so why is this pinl hump so important well this goes along with comparing it to your scan tool data of what's called millisecond pulse width right that millisecond pulse width is the amount of time you're actually spraying Fuel and if you were to take the cursors on your scope and line them up to an injector amperage type of waveform pack pattern there that would line up perfectly from when it's actually spraying fuel when it begins to spray fuel to when we tell it to shut off now the bottom the second part that circled there that represents when the injector's told to turn off so had some comments in some videos it says you know I just got my butt kicked on I thought that I had a restricted injector and stuff um other scenario could be it could be a leaking injector so we're going to talk about all those scenarios as we go on throughout this video here but we'll come back to this that's a great way to tell if the injector is actually turning off or if it's leaking or anything along those lines then we came out with sequential fuel injection basically the same style injector these are usually you know 12 to 16 ohm injectors right same style injection however the difference is we came out with something else that's not really involved with the fuel system but we had a cam shaft position sensor now once we knew where the cam shaft was located now we say we don't need to spray it two times and just have a bunch of fuel puddled on the back of a closed intake valve because I know exactly when that intake valve is going to open per cylinder so sequential fuel injection came out that did away with a lot of the carbon cleanings and stuff that we used to have to do on vehicles so the cars started running even so much better and this is just how everything's evolved there is another type of fuel system out there that's not real popular anymore but this was called CPI central port style in ction this was a big time General Motors type of thing what this did is the bottom part here were actually called poet valves and each one of these would go inside the the uh combustion chamber of one of those Vehicles now I had the electrical injectors on the other side of this also had a fuel pressure regulator hooked up to it didn't have to have a vacuum hose on it because this is all down inside the intake manifold now these actually even though this was you know Central sequential which means it should only be spraying fuel one time these had a bunch of carbon problems as well because the tips of the actual injector part itself the popet valves those were exposed to a lot of carbon inside there so these if you've never come across one of these you may not because those aren't very popular Vehicles anymore a lot of them are you know in Salvage ARs and stuff but those were another style um we have two styles of that the first early style was not actually sequential the later styles actually Incorporated in the sequential style injection inside there so again the basic fuel test of testing fuel pressure fuel volume and stuff that would apply to any one of these systems even a carburated system however once we start getting into the testing the actual injection part that's where it's going to differ from one one type of system to another so when I test an injector so you might say to yourself okay so we've been talking a lot about injectors how can I test it so we all know that one way to test it would be with an actual ohm meter and I can test the resistance the coil of windings that's inside that injector and that should tell me if it's shorted if it's open anything along those lines any one of my videos I always tell you I hate doing static type of test like that because there's no actual current flow happening here so just like when you have a no start and you're wondering am I getting a signal from the PCM to tell the injectors to turn on and off that signal is usually coming from either the cam or crank sensor they had these little guys called noid lights right so there's a different set and you know depending on what type of terminals they had for the injectors you would just find the one plug it in and while you crank the car over it should be blinking on and off but again it's not a loaded test that was the downside to this it's a quick go or no-go test but it's not a loaded test so just testing the resistance of these guys this would help me determine if I had shorted injectors and stuff that was a big problem back on the early General Motors cars where injector drivers would short out because you have one or two bad injectors on the vehicle sometimes you'd have even more than that and cause all kinds of drivability problems but there was a couple companies back in the day that had these really cool tools that were not seeing it but I'll find it for the second part of the video that was really cool that would allow you to do a loaded test on here so you'd hook up your company was called OTC here it is I found it so I'd actually take this tool and I'd do the same type of test result I'd have to have power and ground right so I'd hook that up to my battery cables on the car I'll show you this in action here when we get to the Hands-On part and the other lead coming out of it would just simply plug right into the injector and it had some adapters in case the injector leads were different then I'd put my voltmeter leads inside here so I could turn it on ohms and just get the same type of static type of test results of let's say this thing turned out to be 12.3 ohms or something of resistance but the difference is is I can then go ahead and flip my meter over to the voltage scale and I can do a voltage drop and actually select the amperage scale depending on the resistance of the injector push the button and now I'm doing a loaded test right which was a huge benefit I didn't have to take the injector off the car to do this I could do it right on the car very simple and easy to do so we'll I'll show you that in action I don't know of any manufacturer still making that tool um so you got to be old like me to actually probably have one of those in your in your diagnostic Arsenal there but that's another way to actually test the the Integrity the electrical Integrity of the fuel injector now again if you're using a lab scope you get a good insight as to if whether or not this injector shorted or any of those kind of problems that we used to have to do with a tool like this with Mod modern day technology of looking at the waveforms that a labscope displays for you now we also would like to do an injector flow test so one of the comments that I just recently read said it was a Toyota Prius or something that you know had some restricted injectors and how can I test that on a car without having to take the injectors out of the car and put them in a flow bench or even if you don't have a flow bench somehow physically watching it so I'm going to show you guys how to do an injector balanced test on a vehicle so we can power up and develop fuel pressure into the fuel rail then we can one by one turn the injectors on whether we're using an old-fashioned tool like this or whether we're taking advantage of the bir directional controls of our scan tools so now every time I turn an injector on it's going to drop so much fuel pressure and then I go to the next injector it Powers the fuel pump back up get the fuel pressure back in the rail and then I'm just going to be recording ing those results of each one of those injector drops which is going to tell me if I have any type of carbon possibly restricting those injectors we can also use a gas analyzer gas analyzer has got a lot of benefit to it I'm going to have a section of these um Advanced Diagnostic videos that talk about all the benefits and how to use a gas analyzer and stuff it's not just for emissions testing but let's say I had an injector that wasn't shutting off right so it was a leaking injector well that's not a problem if you have a gas analyzer right I can take the spark plugs out of the out of the cylinders and I could take the wand from my gas analyzer and stick it in each one of those holes and if I had a leaky injector gasoline has hydrocarbons right so hydrocarbons value is going to start to Skyrocket in the cylinder that has the injector that's leaking fuel right I also can actually do a dynamic test with my gas analy ier by doing an injector balance test and instead of looking at the fuel pressure drop I can actually look at the hydrocarbons readings right so if I go ahead and I tell an injector to shut off I should see a difference in the hydrocarbons coming out the tailpipe on my vehicle I also have flow benches which we're going to talk about this guy here this is probably the best way because now I get a visual representation but it's also the most timec consuming way to actually test a lot of the injectors because you have to remove the injectors from the vehicle some cars that's easier to do than others as you guys are well aware all right so with that being said I got some fuel system tips and tricks that I'm going to share with you guys real quick and I'm not going to read these word for word or anything but these are common problems and you know shortcut ways of addressing some of these problems so one of the big things that I I'm just we'll leave this up on the screen so you guys can read it but one of the big things is if you have a shorted injector a lot of times you can do a little trick where if you take a battery load tester and load down the battery that extra load you're placing on the charging system will help to uncover that shorted injector whether you're using a scope or an oldfashioned tool to determine if it's shorted or not doesn't matter it's a it's a good way to actually find those those injectors that are a little bit harder to diagnose as having a short on there also if you do have shorted injectors and stuff the idle air control or whatever they want to call it on the manufacturer type of vehicle that you're working on that those iak counts are going to give you an insight as to whether or not there's a shorted injector on it carbon buildup is always a big concern especially with gasoline direct injection coming coming to fruition on most of modern day cars so those that carbon buildup is something that we got away from with multi-port fuel injection but it's coming back as a pretty much a common day problem where we have to address that a modern day cars and again I told you in part one all my little six goto pids and how I can use fuel trims to help me diagnose if it's a fuel related problem or if it's an ignition related problem so again I'm not going to read these word for word you guys can kind of see them but I got a couple different screens of the of the little fuel system tips and tricks in general whether it be with you know the conventional fuel pumps and stuff or whether it be with special fuel injection systems whatever the case happens to be so now let's fast forward into more modern day times here gasoline direct injection what's the difference between that well on a gasoline direct injected car the injectors look different in appearance right they're usually a lot longer but the actual part that sprays the fuel is directly inserted inside the combustion chamber as opposed to going inside the cylinder head waiting for an intake valve to open up so because it's directly located inside the combustion chamber well that's where all the extra carbon's coming from so the tips on those get you know carboned up on a relatively um Regular type of basis there so you'll notice from the screen here how this kind of looks in a cutaway engine that I that I got from one of the car shows that came to the Cleveland area here they had these engines on display when GDI was pretty much brand new so part of this is also it's all integrated together right so if you notice the top of that piston there the fuel as it sprays inside the cylinder that cutout in the in the Piston is actually directing all that atomized fuel right to that Center electrode of that spark plug so we're going to have the most efficient type of fuel injection system with gasoline direct injection and atomization has really improved because we've got even higher pressure so even with even higher pressure the fuel molecules want to atomize much better again there are some disadvantages to this one of them being carbon that's the the biggest disadvantage another disadvantage is the extra fuel pressure becomes a danger or concern for us as technicians so we have a low pressure fuel pump that is going to basically take fuel out of the car at 30 to 60 PSI roughly and pump it up to the high press fuel pump now this high- pressure fuel pumps being driven off the cam shaft right and it's kind of operating just like an old-fashioned carburetor type of fuel pump where it's got a lever of some sort so there's going to be an extra lobe on the cam shaft probably have a little lifter of some sort inside there that's actually pumping this now that actual pumping method here takes that 30 to 60 PSI and increases it exponentially right it could be it could be a couple hundred PSI it could be you know over a, PSI side depending on the car and the driving conditions that you're working on so here's where the low pressure fuel is coming into the tank there's my little low pressure fuel test port with the cap still on it here but on the outside of it it can't use any kind of little push style connectors like we're used to with the lower lower pressure systems everything is screwed down and in place and these are one-time use lines so the reason why they're onetime use lines is because once I torque it down it's going to distort that ball shoulder type of socket there which means I'll never get it to tighten down with the exact same Distortion so it's going to want it's going to want to leak right because we got such higher pressure so if you take this apart let's say somebody comes in for head gasket job or something and you have to take all this stuff apart to get the head off well that means keep that in mind when you're pricing out the job that you're going to want to include the money in there to replace whatever high pressure fuel lines that you had to disconnect or disturb throughout that process there now with that being said I've got at the bottom there three fuel injectors you can kind of see the center one has been cleaned up um but the two outside ones that's what the that's what the inputs of or the outputs of the injectors look like where they have all the carbon built up on there also anytime you service a GDI system itself so you're changing an injector or doing whatever the case happens to be there's little clips that hold the injectors on to the fuel rails so here's a fuel rail with an old-fashioned type of car and we all know that the injector would pretty much just kind of push into place it's got this style has an O-ring the new Styles usually have like a Teflon o-ring much much better design and then there'd be like a little clip that would kind of hold this in place well you want to change those clips out too if you start to disturb any of this always want to be changing the seals anytime you pull the fuel rails or anything out of those vehicles just for safety reasons because of the higher fuel pressure that's involved but this is how that high pressure fuel pump is actually designed here so here we can see this is a little cap that would go on this particular car on the back side of of where the cam shaft is actually exposed in the bottom corner you could kind of see how there's a cam lobe that's going on that roller lifter so a lot of times you'll get some trouble codes that has to do with the high pressure fuel system the car will still run with the the low pressure system um but you'll get some trouble codes and it might be that the cam shafts worn out right or it might be that the lifter's worn out you could kind of see I know I didn't get a real good picture of this from the auto show but there is wear on that roller lifter tip there because we're dealing with such higher pressure there's a lot more fumes involved so you don't want to be smoking around these systems anything along those lines you want to pay attention to safety because you can actually inject that gasoline pierce your skin and go right into your right into your hand or whatever with this so if you're working on a vehicle and you start to crack open those those screw type of lines of the high pressure fuel system it's like being shot with a with a fire hose right it's a lot higher pressure than getting shot with a with an actual garden hose so the volume of pressure and the overall pressure is very dangerous for us so we always want to make sure before we open up a fuel system a high pressure fuel system that we go ahead through our scan tool read the fuel rail pressure there's no way for us to get a mechanical reading on a high pressure system a GDI system we can get the low pressure side that's the one that's coming from the gas tank up to the fuel rail but there's no way to get this mechanical wise so there's a little sensor that's going to be on the fuel rails that's going to tell you what the high pressure of the system happens to be so you take your scan tool you plug it in you look at that fuel pressure and if it says that it's 800 PSI 1,000 PSI whatever the value happens to be you want to relieve that pressure before you start to crack open those fuel lines so you could do that a couple different ways easiest way I mean sometimes your scan tool if you got a halfway decent one allows you to do that by directionally but let's say it doesn't you can just find that fuel pressure relay that we were talking about pull it out of the car and crank the car over the car might start for a couple seconds it may not start at all but just watch that data stream on your scan tool until that pressure gets down you know to 40 PSI or less because we've all taken fuel lines apart that were 40 PSI it's not going to pierce your skin cause any kind of problems so there's a couple little housekeeping type of things when we're talking about gasoline direct injection because of the carbon that's going to be built up inside that combustion chamber around where those fuel injectors go it's also very hard to get those injectors out of the combustion chamber so there's a lot of companies out there OTC ly a lot of different companies that make little kits to help you pull so if you ever taken injectors or glow plugs or anything out of a out of a diesel you kind of already am used to this right you got to overcome that carbon buildup there so I'm showing you again you know the carbon issues are the biggest problem with any vehicle that has gasoline direct injection on it another little housekeeping rule of thumb that I can say is when you take the engine covers off a modern day car gasoline direct injection you hear this you hear that clicking of this thing going back and forth so those those engine covers are made so that the car owner inside the car doesn't want to hear that it sounds like you got a bad Lifter on an old-fashioned car so and all the way how all the wiring and everything is all laid out they don't want nothing touching the fuel rails because if anything's touching the fuel rails the harmonics of that clicking that you're hearing of this fuel pump actually get get um exponentially louder and it kind of works as like a microphone so if you take something apart put it back together make sure the how the hoses the harnesses everything are back in their little wire looms the way how they're supposed to be definitely put that engine cover back on the car you know don't leave it off the car for any reason because the customer is going to come to you and they're going to say hey I think I I don't know I think I need an oil change or something because it seems to be ticking or something and sometimes you still get that right sometimes you customer comes in maybe they were outside of the car so they pulled in somebody's driveway they got out of the car to go knock on the door or something and now they're hearing as they walk you know to the door on the on the guy's house they're hearing that clicking or ticking and they're like oh my old car didn't sound like that right so sometimes they bring it to you and they say it's making this weird noise but that's a normal scenario they just don't hear it while they're in the car because number one they're in the car number two that engine cover is primarily designed to help cut cut down on that type of noise there so here's another picture of different types of wear patterns this is a more closeup of different types of wear pattern so there's a worn cam lobe there um if there if it's got a lifter of some sort so this is a European car and they got these little covers that go over it you can kind of see how the wear pattern gets displayed there so it's vitally important that we always use the correct oil when we're dealing with these cars so it's not just something that the oil fill cap tells you to use dexos or tells you to use a specific type of oil you definitely want to do it because we don't want this to fail on us that's a very costly type of repair for the consumer that has a car and maybe they took it to some discount oil changes and they weren't using the right viscosity or they didn't have all the certifications of the oil whatever the case happens to be so the oil quality and content and everything is is of vital importance there so at this point what I want to do is I want to turn our attention to do some stuff on the car we're going to do some stuff with the scan tool we're going to do some stuff with the scope we're also going to concentrate on doing this because a lot of the stuff that we talked about I can show you with a really good view of using this type of tester right here okay so we're going to start off relatively basic with our test here and I'm going to use the the special fuel injector tester from the old days um you don't need that to do this first test it's just a static test so I have it hooked up to the fuel injector just got it plugged in I could take my two leads for my meter and just touch the two terminals on the injector but I'm going to put it in there and you can see that from the meter screen we're reading roughly about 16 ohms or so so that's the static test again I don't like static tests because it's not being put under any type of load so instead of hooking up the other two leads of this tool to the car's battery I've got this little 12vt power supply I'm just going to power the power supply up and basically what I'm going to do is I'm going to put my meter on voltage and now I'm going to do an actual loaded test um I could do a coil test or a balance test I'm going to select 2 and 1/2 amp of the balance test and I'm getting a reading of the voltage drop so we know we're given the tool 12 volts with the resistance that's occurring through the injector there I'm seeing the voltage drop so it's an actual loaded type of test I can hit the little start button on here and we can see what that does to our reading there and we can see that that voltage drops even further once we were to tell this injector to actually open up now the balance test on there would actually cycle the injector so it don't want to pulse the injector kind of like if we were using the the Noid lights from in the past to actually go ahead and spray the the actual fuel out of that fuel injector now that's a great test for doing an injector balance test or an injector drop test on a car again I'd fill up the fuel rail I got a better way to do it which I'm going to show you using the scan tool and also a fuel pressure gauge but that's another way if I didn't have a scan tool if I had a a tool that can actually pulse the injector I'll be able to do that same type of test I just have to cycle the key each time to build up fuel pressure again now the other test I wanted to show you here was just acquiring a fuel pump waveform so I got my low amp inductive current probe here I got this from AES wave this current probe by the general look of this you can find this made by many different manufacturers so you can find this exact same current probe that has the words OTC on it and you're going to be spending close to 400 bucks for that thing or you could buy this one here from AES which is a much more affordable rate it's the exact same current probe so that's a good thing so I'm going to turn the scope on and we're going to hook up to this this fuel pump that I got actually oscillating on the bench over here so I'm going to power up the scope I'm going to say okay there wants to perform a little update for me so that shouldn't take a real long time to do we're already at about 50 something per. so once that's done 100% there the scope that should go away and we should see the scope pattern better all right so let's go ahead and hit the scope button again now it's searching for the device it's going to read the data so it's connected to the scope module that I just have on the dashboard of this car I don't much care about Channel a cuz I got the scope actually in Channel B so I'm going to go ahead and turn Channel B and focus our attention solely on channel B right now turn Channel a off and again for this particular scope I got to tell it that I'm using some type of inductive amp clamp so I'm going to go to probe setting I'm going to scroll on up the list here I'm going to use my 6 5 current clamp with the first rating here I'm going to say okay that all looks good now again the scope is in Auto sampling so as soon as I clamp this around the the one of the two wires there I'm going to start to display away from it's not going to look pretty because it's in Auto sampling I'm going to have to make some scope adjustments here whenever I'm measuring current current is the same whether you're on the positive or negative side of the circuit which makes hooking up a clamp like this very very easy so it doesn't matter if I went to the power wire or the ground wire I'm just going to clamp around here and again it's trying it's in Auto setup right now so it's trying to display some type of pattern for me what I'm going to do is I'm going to make this a little bit a little bit more user friendly here I'm going to adjust the time base and I'm also going to adjust the voltage scale here of the actual probe setting here I'm going to go down to Let's say 10 amps and let's see if I got a a better looking pattern here so this would be more accustomed to what I'd want to see for this fuel pump now in all reality there's no fuel pressure going to this so the amperage and the RPM is going to be a little bit different plus this is a low press pump so we're still seeing what I like to call those little camel humps there and if I wanted to determine the RPM of this type of pump or anything um what I'd want to do is I'd want to look for a different pattern right so I can see that I've got some voltage spikes going up on a couple of those a couple of those waveforms there but in particular there's a series there where it repeats itself several times so I'd want to count how many humps I have before it repeats itself and then I could determine how many segments of that commutator there was inside that fuel pump so here's real quick you saw that this took maybe maybe 4 seconds to actually look up to now granted this this pump is on a table but again think about everything we talked about we remove the fuel pump relay with one of our relay testers it has the amp Loop put the fuel pump relay in its place flip the fuel pump relay tester on and then just clamp this right around that amp Loop and it still doesn't take any amount of time and again I can determine stuff like was this the cause of the no start is there a bad part of the the commutator segment in there is there a restricted fuel filter all that stuff can be determined with one quick simple hookup underneath the hood of the car or if it's easier if if the car doesn't um have a very easy access to a power or ground wire a fuel pump sometimes it's easier to go underneath the car most of the time though it's going to be easier to go underneath the hood of the car as opposed to lifting the car up in the air so now I want to focus our attention on this guy this is an injector flow bench it will also clean injectors I can do all kinds of cool stuff which I'm going to show you as the video goes on here this is made by a company called autol very close to autel but it's a whole different company so a tool with the injector flow bench I have the ability to not only test the injectors I can clean the injectors on the back side is an ultrasonic cleaner from the top I could take the injectors out of the car place the injectors inside that bath um I recommend this stuff that's looks like it's made by a team for the cleaning solution this is not the stuff that we're going to be see coming out of these tubes here but this is what we'd be be using in the ultrasonic bath there and I can clean the injectors manually that way now I don't have to take the injectors out of the car to actually clean them as we're all well aware of there's all kinds of other companies out there I happen to have one by laying um here I would just pour that injector cleaning solvent inside of a onar type of cleaner um Bernie Thompson from Automotive test solution has a whole GDI cleaning type of setup you know so whatever you have there's options to cleaning the different types of injectors that you may come across here so but cleaning the injectors again cleans the carbon buildup off of it especially if they're restricted injectors so every time you tell the injector to open it can't spray the fuel out because of the mechanical restriction and plus remember carbon acts as a sponge so it sucks up some of the fuel what's nice about this flow bench here is the injector should be m match the flow rate of the injector should be matched from the manufacturer and over time as they get restricted you will actually see that you'll also be able to tell if the injector shorted you'll be able to tell a whole host of different problems plus when I'm cleaning the injectors I have a couple ways that I can clean them I can actually clean the injectors the conventional way where the flow comes in from the top and then comes out the bottom but I can also go ahead and do a reverse flow type of test on the injectors where I can go ahead and back flow plus SC injectors as well this tool is worth every single scent now there's other manufacturers that make a flow bench like this you know one of the companies out there is um is a company called launch launch makes a tool like this as well what I love so much about this tool is this tool it's capable for doing conventional style injectors whether they're throttle body port or sequential but it also you'll see it's a new modern-day version where I can do gasoline direct injection which requires much higher voltage to turn them on and off so it comes complete with all that and it's a fraction of the cost of some of the competitors's tools that are on the same Market here does the exact same thing so you can kind of see I got a couple different things function one is just alra Sonic cleaning that is if I had the injectors in the bath in the in the back it's going to pulse the injectors on and off and it's going to Rattle them around to help clean the injectors very very precise way and what's nice is if you choose this way to clean it you can test them before the cleaning and after the cleaning to see the actual difference that that's occurring here I also have idle test I have medium speed test high speed test acceleration test a leak check test which is very beneficial I'll come back to that um medium speed spray value test High speeed reverse flushing so I have several different types of testing of the injectors that I can do now I'm not going to go through all all four or 13 different types of steps on here because I think you'll get the general gist each one is going to do something different now all of those different speed types of tests is going to affect that the rate at which this is actually going to pulsate those injectors so obviously at idle you're not going to have as much fuel flow or anything um at high speed you're going to have a much higher fuel flow rate I can also adjust the pressure going to the injectors that's with the actual pressure buttons over here on the side so depending on the type of injector if it's throttle body it's going to be a lower type of pressure You' kind of want this to emulate whatever the original fuel pressure is so it's not going to go up to you know a th000 PSI but for gasoline direct injection but remember on those GDI cars you're giving it you know roughly let's just say 60 PSI or so of pressure which I could definitely acquire that type of pressure and then the high press pump is what's actually boosting it up on GDI from there the little drawer the little storage drawer I love that it's got all the different types of injector type of adapters inside of it comes with you know the different O-rings and stuff for the ceiling of it so it's a very complete kit overall in my opinion and I love this because it's great not only for servicing and repairing vehicles and being able to diagnose them you know if the problem was an idle related problem or whether it was a high-speed problem I could simulate those exact same conditions but it's also great for the training environment so you can actually see what's going on so before I power this up I'm going to do it a couple times because the way how this is designed some of these little flow measuring tubes are recessed inside the machine so you can't actually see them but you can see that they're graduated so in essence when it's done after each one of the tests is done I should be able to match up the actual volume of fuel that's actually being sprayed there so we're not actually spraying fuel we're using uh odorless mineral spirits inside the machine here for the flow test but you can also see the injector spray pain patterns now these are all the same injectors they came out of a car they should all be properly balanced and everything and they should all have the exact same spray pattern if they're not restricted in any way so once I turn it on you'll be able to see the spray pattern and if you see it coming out like a like a actual water hose that's not good you should see like a like a conical type of injector spray pattern on most injectors not all injectors come out like that but on most injectors and you should see the atom ization that's occurring here so just for sake of video I'm just going to select um function number 10 which is a highspeed test and I'm going to say go ahead and start it I've got the the pressure adjusted to about roughly 50 psi on here now we can actually see the injector spraying the fuel so I'm looking primarily at first up at the top and we can see this one definitely is spraying has a much longer spray pattern in the center and I can see the ad ization occurring but this one here and these other ones have a better atomization not as much of a cone shaped spray pattern injector number one over there is probably the weakest out of all four of these so this could be the reason why you have a cylinder number one type of misfire complaint I'm going to do it a couple more times I could adjust this working time so it stays on longer um but I'm going to do it a couple more time so we can actually see the the actual fluid as it rises up coming out from the little recess area here this is only going it pumps it down to to 10 on the actual setup here and I also have the actual pulse width adjustment so I can change a pulse width on here I got the little up and down arrows so I can make that pulse width either faster or slower um I'd have to do that while the test isn't running to actually have that number change and I also can adjust the the actual injectant time time here that it's actually being displayed so if I were to change this and say hey let's make this run a little bit longer let's go up to 20 so we doubled it and the pulse width let's make it so it's uh a little bit more than the than what we had before I think it was 10 before so let's do 11 and then I'm going to go ahead and hit the start button again and now I'm spraying the the fuel again but notice by just making those Chang changes of the pulse width notice what that does to the actual spray patterns there and this is just like how your car actually operates so that's the real Theory and benefit of using an injector flow bench I can simulate the cars operating conditions under different types of different types of uh driving conditions whether it be idle whatever the case happens to be and I can actually physically see the actual flow patterns and I can see that this one here in the middle is probably the one that I like the best out of the out of the four that are being displayed there now if I wanted this to fill up I would have to close this I've just got it circulating right now but now it's actually going to start to since I closed the little valve here it's not going to circulate back in the machine and eventually that you'll start to see that on the camera here so I have a lot of different types of tests that I can do with this and again I can still do the cleaning I can can also do an injector leakage test so let me explain that real quick I'll let this run it's not the injector leakage test but I'll let this run so it just builds up that volume of fuel inside each one of those graduated cylinders um the injector leakage test if I were to select that from the function menu that's going to pressurize the fuel rail but it's not going to send power to the actual injectors so if one of the injectors was leaking fuel at the time I would see that dripping down inside there and that's going to cause you know failed emissions tests it's going to cause all kinds of problems like that um running rich type of conditions it's going to affect your fuel trim obviously your O2 sensor values are all going to be skewed so at this point we can start to see the actual fuel levels once the test runs out there since we're flowing liquid in there right now we do have some bubbles so once it actually stops flowing the liquid you'll give it a couple seconds and you'll let the bubbles dissipate there and then we can actually read it on the actual graduations there and we want to make sure again all of these injectors should have a pretty similar matched flow rate if they're not matched for some reason it could be because of an injector electrical problem such as a short or an open or something along those lines or could actually also be from a restriction problem so if I was going to take these out of the car and follow the the manufacturer specs here I'd probably first hook them up into the front part of the machine here and do a leakage test on it then from that point I'd probably go ahead and do an overall flow test and then get some type of Baseline reading and then I'd take them back out of here it's real simple you just undo these little knobs here pull them out pull the injectors out put them in the bath in the back again I'd use a different type of fluid for that I'd use the injector cleaning fluid put them in the bath in the back let it do its ultrasonic cleaning again I have control over the time and the pulse rate and everything for every one of these tests I'd clean them and then I'd put them back in here and I'd do the same type of test again to make sure that I made a noticeable Improvement in either the way they flowed or you by looking at the injector patterns or maybe they were leaking before and they're not leaking now or possibly the flow rate was just all screwed up so looking at these right now you know they're kind of balanced but this one here the third one is definitely the lowest um I know you can't see the numbers real clear on the video but this one's about 30 where the one right next to it on the left is probably about 35 36 so there is a big difference between them and if I went through the process of actually doing the cleaning and everything I should see that those things should pretty much all be level and straightforward there again this is made by a company called a tool and this is a great I can't I can't give a shout out to them enough they make some very very very good Tools in my opinion and they are definitely helpful in diagnosing different types of cars for an affordable rate so you know this is just one tool and they make digital volt meters they make all kinds of stuff so we'll be using a lot not necessarily this companies because this is the only tool I have from this company um but we'll be using a lot of different types of tools that this company does sell just different brands of the tools throughout a lot of our videos as we go through with smoke machine testing for evaps and so on and so forth I mean they got AC related tools they got all kinds of stuff so this is something that you can buy off Amazon or I'm sure they probably have a website you know I don't know I never looked it up but this is this flow bench is very beneficial technically I can do onar injector cleaning with this flow bench too if I bought some hose adapter sets to be able to go onto the car I didn't buy those when I bought this so I can't you know show you how to do that I used my my onar fuel injection cleaning type of setup there um another nice thing too about the encar injection cleaning a lot of times the throttle plates on the car get carboned up we all know that that's a problem so here's a little wand that I can actually take the the air inlet hose off from the air cleaner and I can put this in there and put the air inlet hose back on tighten the hose clamp back down and I can spray some in ejector cleaning onto the car while it's idling which will help clean the throttle plates on the vehicle so there's a whole Oasis of different types of tooling and adapters and stuff and again you're probably may maybe not going to want to run out and buy all the different tools you see in these videos but you know I've been doing this for you know a long time so I didn't run out and buy all this stuff all at once it's over Decades of me being a mechanic so just you know if you find something of interest and you think it's a good benefit official tool shop around a lot of times I started with the lower quality of a tool and then eventually as as I made money using that tool I'd replace it with a higher quality you know stuff that you guys have been doing for years anyways so next what we're going to do is we're going to focus our attention on this vehicle over here um what I want to do is I want to do an injector drop test on this vehicle I'm going to use my scan tool I'm going to use a fuel pressure gauge and then I'm also going to hook up to a fuel injector on here now the precursor to that is I've got the engine cover off and this car the way how it's designed has a very unique thing with the mass airf flow sensor hose so once I take that off I'm not going to have it's going to run poorly right so it's going to run poorly I'm not going to be able to run it for a long period of time I'm going to set some diagnostic trouble codes because in order to get at the injectors I got to have that engine cover off which means the mass air flow is not going to be able to suck any kind of air going past it so I just wanted to throw that out there before we we focus our attention on this car but again we're going to start with the injector drop test for one of the comments that we had earlier of with that Toyota Prius um this is how I would do it you know this is a very quick easy way to actually do this test to determine if I had you know a dirty injector of some sort okay so I've taken a conventional style fuel pressure gauge hooked it up to the fuel rail on this on this uh plug-in hybrid type of vehicle I'm going into my scan tool I already communicated with the car I select engine control module from the control unit I'm going to use a bidirectional test here that's going to be under active test and I pull up a whole list of stuff I have control over I'm going to go to fuel system and what I'm going to do is what's called fuel injector balance test so I'm going to click on the fuel injector balance test and it's going to tell me some stipulations right it's going to say hey ensure that all the fuel lines are connected all that kind of stuff um connect the fuel pressure gauge up each injector can only be tested one time I'm okay with all those I'm going to say continue fuel injector one is going to be tested so that's the first injector in the rail I don't have to have a mechanical hook up to that that fuel injector because I'm just looking at the drop that's going to occur here it tells me once I hit the continue button we're going to build up fuel pressure so it's going to tell the fuel pump driver module to turn on and build up fuel pressure and then I'm going to hit the start button and I'm going to measure it should drop once that injector's open once that injector is open I'm going to record that drop and I'm going to go to injector number two and I would do that in this case for all four injectors obviously if there's more injectors on the car i' do it for you know six injectors eight injectors whatever so I'm going to say okay we built up some fuel pressure and I'm going to say continue and we see that that fuel pressure is dropping here right so that simple test of just seeing seeing the the fuel pressure drop per injector is going to tell me if I have any type of restriction or contamination in any one of those fuel injectors it always starts with the exact same Keon engine Off fuel pressure the scan tool is doing it for us now if you're scan tool let's say you don't have a by directional control scan tool and maybe the car doesn't support that test you can do the same thing with an injector pulser test and a fuel pressure gauge so you could take that oldfashioned tool that I had that would require you to unplug each injector and actually plug that tool into the top of the injector turn the key on and off by hand to cycle the fuel pressure and then just push that button and then record that drop but to answer the one comments question that's the most quickest simplest way to do that type of test to determine if you have a restriction in any of your fuel injectors okay so the last little Quick Test I want to show you on here again I can't stress enough guys there is so so much more information available for every one of these subjects I'm just trying to keep the video length and the condensed version um full-fledged training classes are your real solution here but what I wanted to show you is just looking at the injector pattern both voltage over amperage so I've got it hooked up to this car that's running behind me it's not running 100% efficient only because the mass airf flow does H does not not have the the hose hooked up to it at the time I've got a frozen pattern I've already sampled the pattern kind of blew it up there so again the voltage pattern it's both on the exact same injector now the nice thing is there's two wires going to the injector one wire is actually it doesn't matter because that's going to the inductive amp clamp and it doesn't matter which one of those wires I clamped around to the other wire is going to the voltage feed so I have to be on the ground side of that pattern so to determine that I just had the scope live and I poked one wire first without looking at the um without looking at the actual wiring schematic I just Ed a back probe adapter slid it down I saw that I had 12 volts on that wire so that would not be the wire that I wanted I want to go on to the other side to get that successful pattern there so again as soon as I'm looking at the red lead right now um the red picture as soon as that voltage dropped down that's telling it to start building up current in the injector and the voltage Spike that's occurring that's telling it when I Collapse a magnetic field and turn the injector off however that injector doesn't actually start flowing fuel until there's enough amperage built up inside the circuit now if there is a shorted injector that would affect that amperage the the actual inductive kick at the end right so that would be much smaller in appearance if there was was a shorted injector looking at the amperage reading which is the green one underneath it that's going to affect the overall height of that of that pattern so that's going to be drawing a short always draws more amperage so I'm looking at the two patterns together notice are both told to turn on at the same time but the green pattern somewhere around I want to say roughly .58 on the scale there is where I can see the pental hump that's occurring on this pattern and then once I get the trailing edge of that waveform that's when we're told to shut the injector off so if the injector wasn't shutting off that would affect the actual trailing edge of that waveform so again I can go ahead and turn that pattern back on to a live pattern and it's going to pretty much be locked in because of the way how I got my trigger and time base and everything set up but just for your new scope users in here if you happen to be using the autel scope that came with your scanner a quick easy way to get this set up is I hit the little car at the top of the screen I pull up actuators because a fuel injector is an actuator I select injector and then from the right hand part of the screen I have a couple choices so I'm I'm using a multi-port point fuel injection type of injector I'm looking at the injector voltage I also have a selection for injector voltage and current which would require the two channels to be hooked up at the same time so that's how I actually acquired that signal but I wanted to show you that because technically if I were to start accelerating the car or whatever that on time should obviously change and relation because the faster the RPM's going the more fuel delivery the car is actually requesting and requiring at that time also that's a great way to determine if I have an electrical Integrity problem problem with the fuel injector itself that Integrity problem could be a bad injector could be a circuit problem always remember that could even be a PCM problem so I Incorporated a little bit more Hands-On into this this educational video again I'm I'm just scratching the surface on all of these um I could go on and on about any one of these subjects I'm just scratching the surface if you guys didn't mind the longer length duration of a video in the future for the other educational videos I'll incorporate more handson into those those um types of classes that we go through as well so again go ahead and remember to like And subscribe to this channel definitely comment I read every one of the comments I try to respond to every comment let me know if you guys think I'm doing a good job if you guys want me to see see any type of changes on my part let me know I'm here to try to help you guys

Channel: Electron John - The Drivability Guy

Views: 3,743

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Id: nuKMXd3fm74

Length: 86min 46sec (5206 seconds)

Published: Fri Feb 23 2024