Fuel Injector Testing: Noid Light vs Power Probe vs Test Light (Honda)

[Music] all right I got this Honda here with a misfire the number-two cylinder here is missing I already checked for spark so we got spark here now I need to check and make sure we got control from the computer on that fuel injector and I figured I bring you along show a couple different ways you can test them talk about it alright before we get started it helps to know a little bit of background on the system you're testing in this case a fuel injector represented by the blue there every fuel injector needs a power and a ground so means battery voltage needs a ground most systems get their battery voltage rate from the battery itself they can run through a fuse it can run through a relay sometimes they do run through the engine computer but the bottom line is they need a power and then they need a ground and most systems ground it through the engine computer that's how it has control of the fuel injector so when it seat receives all the proper inputs the computer grounds it at the correct timing and then that sprays fuel out through the pintle there so when we go into our checks we want to see a battery voltage and we want to see it ground and in this case it'll be a pulsed ground because the engine computer is not going to be grounding it all the time it's only gonna do it when he wants the fuel injector to turn on and so it's represented by this little graph here this is what it looks like if you're looking at it on a scope you see the battery voltage this is represented by battery positive usually you know 12 to 14 volts wherever your system is and then as soon as the engine computer wants it to turn on it grounds it and so you'll see that signal go to ground and then it grounds it for a certain length of time and then it turns it off and that's how long you're feeling ejected fires right there and then once it's done it takes the ground off there removes it and then you'll have a voltage spike and that's because the internals in there once you've run power through something it develops magnetic field and so this is the collapse of the magnetic field inducing a voltage spike and so that spike will spike way up and it'll come back down and usually when you look on a scope if you look close you can see a little hump right there and that's the pintle movement right there of the fuel injector and then it goes right back to battery voltage and then it repeats the process the next time the computer wants to fire it so there you go just a little background now let's get started testing the first test I'm gonna do is with the noid light I'm gonna use this noid light set from OTC model number three zero five four e and you can see that's that's how it comes I'm gonna use this GM multi tech - it's got really thin really thin connectors should be able to get in there without doing any damage to the connection usually in this set you can find something that will match the fuel injector on your vehicle this set the e on the end of the model number means it comes with this extension which is kind of nice you can put the noid light inside there and it carries it along so that you can like put it on the windshield in case you have an O start that's kind of nice kind of handy but anyway let's get started to injector light flashing there be no different pick it up you could see this flashing Computers control on their we don't know injector if the windings in every because obviously we have a disconnected this way is easy but we can't tell if the current is flowing through that fuel injector try something else all right on these Honda systems we don't even need a wiring diagram we can just simply see each one of these fuel injectors has a yellow with a black stripe wire on it right here yellow and black yellow and black yellow and black and yellow and black right there every single wire and then on the other side we have a color so Brown was that one red red blue and then a solid yellow and so we know that the wire that's the same on every one of them is going to be the power and then the other side is going to be the ground which the computers controlling so now we'll just grab our test light look for a battery voltage look for ground and control all right now we'll use a test light to check and very similar to the noid light differences we need to connect it up to the battery so first we'll go battery negative make sure our test light works and it does now with the key in the on position we just take our test light and we just need to see if we've got power on here so you can see it I'm just gonna touch inside there I'm not gonna jam it in there just touch and you can see we got power so we know we got power coming in here now we got a check for ground but we need the vehicle running for that because the ground is controlled by the computer so we'll put the test light over to positive we'll turn the vehicle on will check for ground now we'll just do the same thing on the other wire we're looking for a pulse just touching it in there you see we have control that's how you check it with a test light slightly more work than annoyed light set but not not too difficult the only thing makes it a little more difficult as if you had a know start it would be hard to be cranking it and see your light you'd probably need an assistant so but pretty easy alright next I'm gonna use the power probe for to check the fuel injector this power probe the power probe force have a fuel injector mode on it just kind of nice and when you look at it you know the red and green lights will flash meaning a power ground and it'll show the battery voltage it'll show the ground and it'll show the inductive kick there and it'll also show the injector on time so pretty neat little tool you get a lot of info from it and I'll just use a back probe similar to this will back probe the connector you'll get our connections on power all right now you can see what the power probe looks like powered up it defaults to voltage I have this wire with the connection on the end there so I can just plug right into my back probe so I'll just plug that in be able to use it they also make just a little tip that you can cinch since voltage and ground that's what's nice about these because you're connected to battery power and battery ground this will sense this will sense battery voltage and it'll sense ground also whether you've got a good ground or not makes it real easy just one touch and I'll tell you ground or voltage definitely makes a check in for power pretty easy so we'll go just click mode we use the down arrow we'll go down to fuel injector fuel injector right there [Music] just turn that sound off there you go we've got good power and grounds which we already knew injector pulse is at about four point one nine milliseconds we've got a good voltage spike of 66 we got good ground 0.24 and our battery voltage for 14.3 so with one simple test you can see this really did give us a lot physically see in my mind you know the computer is giving a ground and then letting off and then we've hit the spike the only thing we can't see is the pencil hump movement of the fuel injector so these tools really handy to have for doing stuff like this I tend to forget about it and just use annoyed later tests like this thing seems pretty cool I mainly use this to do power windows it works great for that so you can see it works great for this - what's up back Probus another known good fuel injector and see if we've got the thing about the same on time and voltage and unclog that injector so that we don't have peel something in that cylinder very close to the same just thunder 466 battery and ground just over four so yeah it looks the same we know everything going into this fuel injector is good now the actual pencil movement might be bad but at least everything in the circuit is good well there you go that's three different ways you can check the fuel injection circuitry on these Honda's tests like annoyed light or power probe while I'm thinking of it this I know it's a fancy red bulb in there but this is a standard test like it is uh it's not an LED test light like this one I was just using a standard test light and that's gonna be your cheapest route he's running I don't know five bucks to 30 bucks dependent and go to Harbor Freight and get one for four or five bucks the noid said light is around 20 to 25 and the power probe is the most expensive at about a hundred and fifty but you see they all work but they all they all have their pros and cons on on how they work just as a bonus there's a shot of a fuel injector on the scope you can tell this is a good one there's your pintle movement right there and just barely see it in fact if we close our scales down can't see it at 10 you can see the hint of movement right there just a little bit but that's it right there let's see what we got in the bathroom all right this is our suspect you can see we got pencil movement right there too so I don't believe there's anything wrong with this fuel injector sorry she was somewhere else there you go that's just a little bonus obviously if you use the scope you can get all the info but definitely the most expensive way to do it now off camera what I did is I plugged the fuel injector in and I ran the vehicle for a while and I looked at the fuel trims and I saw that the computer was taking fuel away which means that that thing was dumping fuel in there and it wasn't getting burned it was running rich and so I unplugged it let it run for a while longer and then I saw the field trims adjust and adjusted to a lean condition and then the computer had to start adding fuel so that tells me his fuel injectors working no issue there I hope you enjoyed seeing how I troubleshoot the circuitry on these fuel injection systems on these Honda's and as always if this video helped you out make sure to give it a thumbs up thanks for watching okay little bonus footage here all right we got fuel and we got spark now where do you go next if you're looking at this vehicle where do you go next what do we need for that cylinder run fuel spark timing and compression and pretty sure the timing is on because the other three cylinders are working so I'm not I'm not looking at the timing right now but I am gonna look at the compression well I confess I already did look at it and you can see right there 160 in number one number two which is our bad one is only at 70 and then three and four are both at 140 so as you can see there's our problem we don't have compression on the number two cylinder so up next leak test leak down test see where it's leaking out of uh-oh well there you go as you saw from the leak down test we got air coming out of the intake I did check the exhaust I didn't show it on camera there's nothing coming out there so intake valves are bad on this number two cylinder judging by the condition of this engine I would suspect that the valves were never adjusted and that's why they burned them up at least that's my suspicion I won't know until I pull the head off and check them out but anyway hope you enjoyed the little bit of bonus footage have a great [Music]

Channel: Big Dog50001 Automotive

Views: 243,377

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Id: pzeOz-seIQE

Length: 16min 12sec (972 seconds)

Published: Fri Sep 08 2017