The Car is a 93 Z28 with an LT1. Motor has about 135k on it. I figured I'd post here since I know of no fourth gen Camaro forum that can compare to this one.

So anyways, I've been having a problem for weeks now that seems to be getting worse. At first it would happen only once in a while but it now it is happening every time I try to start the car. What happens is it is very difficult for me to start the car. I have to crank the starter for 10 seconds or more before it finally starts. Sometimes it simply won't start unless I put my foot on the gas pedal. Once I put my foot on the gas, it usually starts right up. Sometimes I have to slam the gas pedal while cranking the starter for ten seconds or more before it will start. Sometimes the car will idle poorly for a couple minutes after starting. After that, it pretty much runs and idles just fine. The problem seems to be getting worse so I want to fix it before it won't start at all and leaves me stranded.

I have a fuel pressure guage attached to the schrader valve. With the key on it reads 40 psi at first, but within a couple minutes it drops down to about 20 and continues to slowly drop. With the motor running, it reads a steady 48-49 psi. After shut off with the key still in the on position, it slowly drops back to 20 within a few minutes.

I have heard the pressure should not drop so quickly. I tried to locate the F.P.R. to inspect it, but I could not find it. Where is it located? I know it's on the drivers side near the fuel rail but I could not locate it. Anybody have a picture of it?

If the pressure regulator checks out, should I pretty much go ahead and replace the injectors? Is there any way to test them?

Also, another problem I've been having, not sure if it is related or not, but when I'm in gear with my foot off the gas, the car will begin to stumble and shake even if I am in the appropriate rpm range. I pretty much have to keep my foot on the gas if I'm in gear. Perhaps this also points to bad injectors?

 

I think you might be haveing a fuel pump problem, has it ever been replaced?

 

Not sure if the fuel pump has been changed. I've only owned the car for 5 months. However, due to a faulty fuel gauge I've run out of gas twice, so that could certainly contribute to a failing fuel pump.

 

Not much of a help I know but somewhere I read on here that if you run the car much below 1/4 tank it's hard on the pump as well.

 

In my experience, 9 times out of 10 it's a leaking check valve in the fuel pump that's the culprit of pressure drop after shutdown.
Scott

 

Ok, things got really interesting tonight, but in a bad way.

First let me say that a couple weeks ago I was pulling out of my parking spot and noticed a huge puddle of gas where I was parked. Sure enough, I looked underneath my car and gas was just POURING out from somewhere toward the rear of the engine bay. It wasn't just leaking, it was literally pouring out at a rate of about a gallon every 25 seconds at least. So I shut the car off immediately. However, I shut it back on to check where the leak was coming from and the leak stopped completely. I drove it home and it was fine. I got it up on the jack the next day to investigate but could not find the source because the leak had stopped. It didn't appear again, so I just figured it was a freak occurrence or something, even though I knew deep inside that I would eventually have to deal with it again. But now that I think about it, that was when my hard starting problem really began to get much worse.

So today I'm pulling out of the parking lot and the car is stalling as I press the gas. I can't even make it out of first gear. I pull over and I can smell gas. So I check underneath the car and sure enough gas is flowing out from underneath just like last time. I used up a quarter tank to go half a block! It was dark so all I could tell was that again it was coming from the rear of the engine bay. But since this happened before and then stopped, that would pretty much eliminate a busted or broken fuel line, wouldn't it? I parked the car and got a ride home from a buddy. I'm probably gonna have to tow it home or to a shop.

Anyone have any idea what could be causing this?

 

I would test the injectors. Using a ohm meter, take the injector connectors loose by pressing in on the metal tabs and pull up on the injector connectors. You will see two terminals on each injector. Place the red lead on one terminal and the black lead on the other terminal. Different fuel injector brands measure at different resistances. As long as all are over 10 ohms and measure very close to each other, the coil windings are good. This only tells you that the electrical signal to open and close the injector are good.

You still could have a mechanical leak . The best way to check for injector leaks is to disconnect the battery and pull the fuel rail with the injectors still attached. Connect the battery and hold the injectors above the intake manifold. Have someone turn the key on and see if any visually drip. If any do, you will need to replace them....replace all 8 while your there.

If both of these check out, you will need to check for other fuel leaks. The fuel pressure regulator might be leaking, best checked by removing the vaccum line and looking for raw fuel inside. Not sure where the FPR is on a Camero. There could also be a leak in the fuel lines or in the fuel tank.

 

We posted at about the same time. You need to locate where the leak is coming from and do not start the car until it's found. Pouring fuel and a spark from the starter and the car is toast along with anything around it...including you. I'm thinking for the fuel system that you can purchase some UV dye to put in the gas tank and see where the leak is coming from after pressurizing the fuel system.

 

I agree, it is a huge safety hazard. With so much fuel pouring out, it's hard to tell what the origin is just from looking underneath the car. Once I get it on a jack and get under it, hopefully I'll be able to tell. It just baffles me because what could be leaking so badly intermittently?

BTW congrats to your Tigers!

 

With as much fuel as your describing, you have a big leak. Not sure what is causing it to be intermittant. Possible bad o-ring?

I'm not filmiliar with the F-body LT1's but the fuel rail setup should be the same. Check the fuel lines that connect to the fuel rail. You have to have a disconnect ring to get the lines loose there. Also check the lines at the fuel filter. Check the oil and make sure it's level, not over filled, and doesn't smell like raw fuel. If the FPR diaphram has ruptured it can pour fuel into the crankcase and/or leak out of the vac line somewhere.