GS4_Fiend

iTrader: (22)

If the fuel injectors were leaking, it would leak all the times. That means the car will run richer than normal. If fuel trims are subtracting fuel, that is a good sign.

GS4_Fiend

iTrader: (22)

On the side note, you can pull out the spark plugs and if they black and wet, injectors are leaking. If you want to get techinical, hook up a scope and watch the injector on time

Hayk

iTrader: (1)

I left the gauge hooked up over night on the fuel filter. After about 11 hours, I was at 13 psi (from 42). I'm gonna inspect my fuel lines under the car, because I remember thinking that there might fuel leakage around the tank. My original sway bar was corroded in such a way as if fuel dripped on it and stripped the paint.

Also, Ignition ON does not cycle the pump. I need a multimeter to test my relay.

GS4_Fiend

iTrader: (22)

Whats the point of testing fuel pressure? You dont have a starting problem. Your topic was why your car smells like gas. If you dont see any fuel leaks or smell then your good. If you smell gas only during start up thats normal cuz the car is not in fuel control yet. But it is a big deal if you are smelling gas ALL the time. Fuel trim will help you understand if this is a fuel control problem or not.

Hayk

iTrader: (1)

I do have a starting problem. It takes more cranks than normal to start it up - the reason being is that it has to build up pressure in the lines. It was a lot worse when it was colder, and before I did all that work inside the tank.

The smell is only on start ups, but it's a very potent smell, my friends have commented on it as well.

I'm OCD about my car, so I have to figure out what's wrong.

Power6

No this is not even close. He said the pressure went down in 10 psi in about 30 min? A rev of the motor is measured in milliseconds...

mdbrown

Actually, it sounds like you have half the problem figured out. OTOH, if you truly have a fuel leak it will leak all the time. What you need to do at this point is get the car up in the air with it running and inspect all the fuel lines from the tank to the engine compartment. You'll find it....

GS4_Fiend

iTrader: (22)

I think we got a misunderstanding here... I'm under the assumption that he said he got a leaky injector. A leaky injector will have longer on-time, therefore, the bank that has a leaky injector will run richer. Now are you implying that a car with a leaky injector will not run rich? There are many ways to check if you got a leaky injectors as I mentioned in the previous post.

Now the OP is saying he has a hard to start, now that's another topic.

mdbrown

That would be incorrect. A leaky injector is one that drips fuel when closed (leaking) so pulse width, if anything, would be shorter as the system attempted to lean out the mixture. A rich running condition caused by the system would create a longer on-time for the injector. His symptoms don't really point to a leaking injector though.

GS4_Fiend

iTrader: (22)

OP said he thinks he has a leaky fuel injector. So i enlighten him.

A car with a leaky injector, cylinder with the leaky injector will cause the spark plugs to become black and wet cause of rich condition. The oxygen sensor will sense rich condition and STFT with correct it by leaning it out.

Power6

Yeah I think we have a terminology difference, I think what you refer to would be called a stuck or sticky injector.

Leaky injector to my understanding is one that leaks a very small amount of fuel over time when closed. Usually this is only one injector but could be multiple. It leaks over such time that when the car is off the stored pressure leaks down through the injector putting fuel into a puddle in the intake port. Cold starts, already programmed to be rich by the EFI, become super rich, and hot starts become rich as the pooled fuel has to be used up, very similar to a flood condition with a carb. The other effect is that the pump has to re-pressurize the fuel system on every start since the leaky injector de-pressurizes it. It takes longer for the pump to "catch up" so you have this "rich-lean" condition making hot starts rough. This type of leak is only an imperfect seal, such a small amount that when the engine is running there is not enough time to effect the fuel metering, a leaky injector typically works just fine when running.

I think you are referring more to a stuck/sticky injector that stays open longer than the duty pulse to the solenoid? Sometimes a "gummed up" injector will do this. That would definitely cause some running fuel trim issues and I suppose a sticky injector could easily be a leaky one too.

The symptom of fuel pressure leaking down slowly after shut down is typical leaky injector. There are other causes, bad fuel pump check valve, fuel pressure regulator or actual external fuel leak. I don't know what the typical behavior is here though, most cars leak down some fuel pressure when off, even total loss sitting overnight is not a problem in some systems.

Hayk

iTrader: (1)

I'm amazed by the knowledge base that we have in this subforum. Thank you all for contributing. GS4_Fiend and Power6, you guys are awesome.

I'll update you if I find anything new.

Just to clarify, the fuel pressure tests were isolated, meaning that the fuel injectors were not hooked up to the pressure gauge. The first test was hooked up at the fuel tank outlet, and the second test was at the fuel filter outlet (fuel lines + fuel tank).

mdbrown

If your leak is in the lines between the fuel filter and the tank then get it up in the air and watch it while it's running. You'll see the leak.

mdbrown

You have part of it right. If it thinks it's injecting too much fuel it will shorten the pulse width so the injector isn't open as long hence reducing the amount of fuel injected. At startup the car is in open loop anyway so injector on time is set and does not vary. A rich condition only at startup would never be detected by the system. If it's a leaking injector that requires constant correction then all the injectors on that bank would have a shorter pulse width since it wouldn't know which injector is the culprit. In that instance, long term and short term fuel trim would indicate which bank needed attention, pulling the injectors would likely reveal the leaking injector in minutes.

In any event, if I'm reading his post correctly his problem is in the fuel lines which can be a bigger pain to deal with but easier to locate.

Hayk

iTrader: (1)

I had the car on jack stands, removed the fuel line covers and ran the engine. No visible leaks. I'm kind of disappointed, in a weird way.

This could only mean that the pressure leak is in the fuel tank. I need to go back to the outlet and leave the gauge for longer than an hour.

I ordered a new fuel filter, which should be here Monday. I'll do the test then.