1990 Deville, new fuel pump, new ICM, 40 psi on fuel rail, got spark, start the car and it runs fine for short time then dies. I have found out that something kills power to the injectors. Shut the hood, cuts off. Lock the doors, cuts off. I checked for good body grounds. Removed after market alarm system and checked for fuel disabler PCM, and could not find the right numbers on it to call it a fuel disabler. Still it cuts off with no power to the injectors. Please help before I am pushed to throw gas and a match!

You should have about 40-50 psi on fuel rail. Is there a clogged fuel filter in the line? In line filter installed properly?
Is the fuel pump any good?

It could still be a fuel problem. The only way to be certain is to put a fuel pressure tester on it. Autozone may rent or loan fuel pressure gauges. Easy to hook up to the shrader valve on the engine fuel rail and test fuel pressure. With key on, pressure must be over 40 psi, 40-44psi is what is called for. If pressure drops below 40 after it starts, then you know it was a fuel problem. Either the fuel filter is clogged, or the pump quits because the oil pressure switch is faulty. That switch is tied into the pump circuit, keeps the pump running after the engine is running.

If fuel pressure stays good, maybe problem is in the ignition system. Have the Ignition Control Module tested, also the crank position sensor.

Fuel pump dead or dying. Injection systems need 110 psi, and a pump only doing 30psi will still not run .

This is an ignition problem and is most likely a ignition control module or a sensor.

Hi Clyde:
Since you mention "gas rail" I'm assuming fuel injected.
I'd check the fuel pressure in the rail. Should be around 40 PSI.
If pressure is OK then injectors not working. Time to check cps.
You know the spark side is OK since it will run.

You hook up a fuel pressure gauge to the test port on the engine's fuel rail, and see if the pressure is correct with what is specified for the car. If the pressure is correct, the pump and filter are good, doing what they are supposed to do. Some stores loan or rent fuel pressure gauges. Multiport fuel injection systems usually have high pressure requirements-about 40-50 psi. Check the specs for your car. Usually, the specs call for a pressure with just key on, no start, and a second pressure (maybe 3-10 psi lower) with the engine running.

When it dies, can you immediately restart it, or do you have to wait a bit? Probably fuel or spark related, Any trouble codes present?

Have they changed the fuel filter? What is the pressure in the fuel lines it should be between 30 and 40 psi

Sounds like a weak fuel pump check your fuel pressure.It should be 40-47 psi with key on engine off and with key on engine running it should be 30-44 psi if its not within specs replace fuel pump.

NEED ADJUST SET IGNITION TIMING.MOST TIME YOU INSTALL ANOTHER NEW ENGINE.THE IGNITION TIMING AT DISTRIBUTOR OFF TIME LITTLE TOO FAR ADVANCE CAUSING WEAK SPARKS FOULING OUT SPARK PLUGS. CHECK FUEL PRESSURE SOON AS ENGINE STOP AGAIN DONT TURN ON IGNITION SWITCH CHECK FUEL PRESSURE.SHOULD BE 43 PSI. IF NOT 0 FUEL PUMP BAD OR FUEL PUMP RELAY FAULTY OR FUEL FILTER STOPPED UP.IF FUEL SYSTEM GOOD PROBLEM IN THE IGNITION TIMING.

Will it run for a short time if you squirt some fuel into the throttle body? If so, then concentrate on the fuel delivery system. Fuel pressure at the test port on the fuel rail should be at least 40 PSI. If not, look at the fuel pump, the pressure regulator, and the fuel filter.