Fuel injector? Fuel regulator? Fuel pump? Learn fuel diagnostics

if your car has a hard start at the beginning but then runs fine you probably have a loss of fuel pressure somewhere in the system there are three places that you can lose fuel pressure we're gonna systematically go through each one so we're just not throwing parts of the project the three places you can lose pressure are your fuel injectors your fuel regulator and the check valve located at the fuel pump inside the gas tank what's causing this slow start well there's a lack of pressure and you have to build pressure up every time you crank the key in order to visually see this low pressure we're gonna go ahead and put a gauge on the fuel line and see which one of the three places the fuel pressure is leaking out of you can already see when I disconnected the fuel line there wasn't a blast a fuel pressure like you normally would have in order to diagnose these fuel pressure problems you got to have a gauge now this one costs about $15 and it works just fine when you get a gauge like this it comes with all kinds of fittings so you do whatever it takes to hook it up every car is a little different in this case I actually added this fitting because I suspected a low fuel pressure problem so when I crank on the engine you can see it go up to about 52 psi now every car is gonna be a little different most are between 50 and 60 the fuel pressure on this is in good shape when I turn the engine off it should hold pressure look it's dropping and it's dropping really fast so I know there's a leak somewhere where is it like I said earlier it's leaking from one of three places the fuel pressure regulator is the easiest to check so we'll check it first the fuel pressure regulator is located on the engine on the fuel rail and it has a vacuum attached to it the first thing to check for in the hose is fuel if you see fuel in the hose it's a bad fuel regulator the diaphragm broke you're also gonna notice on that fuel gauge that we put on the system the pressure is going to go up about 8 psi then the fuel pressure is going to go back down when you put the vacuum line back on so you can see this fuel pressure regulator is working perfectly so we're gonna go on to the next step we are going to be looking for a leaky fuel injector and there's a couple ways you can do this you could use a mechanic's stethoscope or you could put a long screwdriver onto the fuel injector and then put the other end of the screwdriver directly against your ear now this is where the skill comes in is knowing what a good fuel injector sounds like it's a little tricky to explain but let me show you what a good fuel injector sounds like so here I'm moving the screwdriver and off the fuel injector so you can hear the tapping sound that it's supposed to make I find that this metal rod works a little better hooked up directly to my speaker to be able to hear that proper tapping sound from the fuel injector what is also very helpful is to listen to all four fuel injectors and listen for something different if you hear something different on one than the other three well that's a good indicator this different sound can point to a bad fuel injector all four of these injectors are in good shape but let's go ahead and listen to all four so you can hear the consistency these injectors sound good but let's take an ohm reading to see and verify that the coils are good inside the injectors so set your meter to ohms and then basically we're going to be looking for a consistent reading across all of the injectors if you see something that's way out well that could also suggest you have a bad injector so all of our readings are around twelve point seven pretty consistent so you can see these injectors are good just to show you that the injectors are in good shape and that they're spraying the way they should we're gonna go ahead and pull these injectors out and we'll hook them up then I'm going to turn the key to pressurize the system and make sure there's no leaking at the fuel injector so you can hear that the key was turned on and there's nothing dripping out of these injectors so again we know the injectors are in good shape so if I turn the key over and crank the car you're gonna see the injectors fire just the way that you normally would now watching them fire into the air is a little difficult to see each jet so I'll put a piece of paper in front of the Jets and this is in slow motion you can start to see each one fire and you can see two points on each jet so I know that everything is clean and they truly are firing just the way they should now your car may be a little different you may have more than two jets so if you have four Jets you're gonna see four points hitting the paper you're gonna want to take a look at any inconsistencies if you see one jet that's different than the others this might clue you in but there's a problem now before you put the Jets back in make sure they're clean but if you take a close look you can see the two holes are the two jets that are firing in that pattern so at this point we've explored two out of the three places we could have a leak we know it's not the fuel pressure regulator we also saw it's not the fuel injectors either the only thing left is the fuel check valve at the fuel pump so I'm gonna hook up a bicycle air pump to the fuel gauge and pump directly into the tank sure enough when I do this you can see exactly where the problem is when I push air into the fuel tank you can see the pressure build and then immediately release the pressure should build and hold now through a process of elimination out of those three points we now know where the problem is now if we put this gauge on to the injector side and where the regulator is you're gonna see that it will in fact hold pressure so I'm gonna go ahead and pump it up to 20 pounds of pressure and you can see it's holding the 20 pounds of pressure so you know the injectors and the regulator are good now we know exactly where the problem is in the fuel pump actually in the fuel pump check valve typically this would involve pulling the gas tank down and $300 into a fuel pump since I know where the problem is I'm not doing that I'm gonna take a check valve that is for fuel and I'm gonna put that in line to maintain my 52 psi of pressure in the fuel line this valve is about $4 and designed for fuel the barb fittings on this check valve are one size too big so I'm just using adapters to be able to get it to fit to my standard fuel line working with this nylon plastic fuel line can be a little tricky so I've made another video to explain all the little details on that now that I have my check valve in the correct direction I'm ready to hook it back up to the system and see if we fix the problem hooking up this one-way check valve is going to save a lot of money because I'm not gonna have to buy that $300 fuel pump and I'm not gonna have to drop the fuel tank it's nice to see no leaks and the car starts up without any hesitation well I hope you found this video useful and if you did I'd sure appreciate a thumbs up thank you [Music]

Channel: Error Code Guy

Views: 4,833,924

Keywords: fuel pressure bleeding off, fuel pressure regulator, fuel pressure gauge, fuel pressure tester, fuel pressure test, fuel pressure regulator symptoms, fuel pressure test kit, fuel pressure check, fuel pressure drops, fuel pressure diagnosis, fuel pressure keeps dropping, fuel pressure leak, fuel pressure problems, fuel pressure psi, fuel pressure problems symptoms

Id: 0PrgUOAG-fU

Length: 9min 51sec (591 seconds)

Published: Tue Nov 07 2017