My car will start and idle for a minute just fine then will sputter and die. It won't restart right away but if I let it sit for a while it will fire back up and then die again. I have been through the ignition system completely. ICM, coil, and opti seem to be fine. I tested the signal to the ICM after it died and did not have any voltage while cranking the engine. After it sat a while I had 1-4 VAC and it would start. I replaced the ECM because of this but it did not fix the problem. The fuel pump primes good and I have 41 psi after it primes. It does not drop 3-10 psi when it starts like the haynes manual says it should. I have good vacuum so I replaced the regulator, once again it did not fix the problem. I have tested the fuel pump relay and I am getting the fuel pump signal from the ECM when the engine is cranking. I need help, I am thinking maybe the fuel pump is not coming on when the engine is running and the car is just running the gas out of the fuel rail and dying.

 

Things are not fine if you loose the 1-4v ac signal. Have you scanned it for trouble codes? The computer is the very last thing I would suspect. If you leave the fuel pressure tester hooked up, you should easily be able to tell if the pump is running. Sounds more like your problem is the opti or opti harness.

 

Did replacing the regulator result in the fuel pressure dropping like it's supposed to when the engine starts? Did you check the vacuum hose for a crack?

The 1-4V AC on the white wire from the PCM to the ICM will disappear if you lose the low res pulse signal from the Opti. That sets a trouble code (but does not turn on the SES light) and shuts down the fuel pump. Scanning for codes would tell you if that is what is happening.