Need help fast!!! This afternoon!!!

[mrvax]

What's inside a fuel pump? I wonder if it has a diaphram similar to an accelerator valve on a carburator. If the pump has a diaphram in it, it could very easily have developed a pin hole leak. This would still get you your 42psi when fired up but also provide a loss of pressure over time allowing fuel to get back to the tank.

Don't replace the fuel rails unless you are certain they're bad. That gunna cost $$$.

I personally would look into the fuel pump having a leak.

 

[forpit2000gt]

A fuel pump can leak back and still give you good fuel pressure. I won't say it can't possibly be an injector, but I think that is the least likely.

 

[95 GT]

Thanks for the responses guys. I really appreciate it. Monday I am going to price new fuel rails and also new pump from the dealer and the pump from Checkers/Auto Zone/Pep Boys, etc. I might be able to get some 1996 or 1997 rails cheap used and they plug right in and have a replaceable pressure regulator. I might also be able to use a known good fuel pump out of a 1992 I have laying around at least for diagnostics. I will keep you posted. For anyone still following this thread I must say I was very impressed with the Accel Fuel Rail Pressure guage. 40 buck delivered to my door, and I installed it in about 10 minutes, and there are no leaks and I can see it from the drivers seat when the hood is open. Makes diagnosing these types of problems easier and looks cool doing it!