makriluc

OK guys, here are the symptoms.
96 Cobra. When I turn the ignition on, the fuel pump primes normally for two seconds. The engine starts but won't idle. Once started, it revs up to 1500-2000 rpm then slowly drops as if it was running out of fuel then dies (it may take about 15 sec). If I press on the schrader valve on the fuel rail, no pressure comes out. Every time I restarts the engine, same thing happens. Could it be fuel pump relay (passenger kick pad)? Could it be the fuel pressure regulator?
Thanks a million.

defconfire

I think the 1996 cobra is a return style fuel system so it shouldn't have pressure unless the car is on.

It could be the IAC sticking partially closed. Will it stay on if you pump the throttle?

Stevecooper

Depending on how long its been setting it will hold pressure in the rails. After the pump has been turned on it will have 40psi.

jwog666

you should have pressure when the car is off, u need to get a fuel pressure guage and hook it to the schrader valve and monitor the fuel pressure. sounds to me like the fuel pump is bad, but the only way to tell is by checking the fuel pressure.

WhiteFoxGT

Try tapping on the IAC while someone cranks the engine over..

If that doesnt work, check for vacuum leaks... See if you can hear a whistling when it is running for those few seconds

Evenexchange

Yeah +1 on the vaccuum leak. I took of my plenum and stuff back when my engine blew up, and forgot to hook up a vaccuum hose. It sounds like someone whistling a very high note, then the whistle dying abruptly.

makriluc

it took me some time to figure it out.
Thanks a lot for all your reply.
Damn it took me all day to diagnose this one. Faulty fuel pump relay. I don't know why but for whatever reason after a few second the relay would open up. I taped in a regular relay and it worked. So I went to buy a new relay and the engine purrs like a kitten. Probably the inner springs or coils....
I just love this car.