I have a 1993 Jimmy with the engine code W. It starts just fine and runs for about 10 or 15 minutes then just dies. Could this be the time where it goes from open loop to closed loop? We recently put new spark plugs in and the old ones looked okay except for one which had some crusty coating on it. Last year we replaced the module on the distributor. The fuel pump puts out 53 psi. Could the ECM be going bad?
Any ideas would be greatly appreciated.

 

Runs and then dies...

You mean while driving or just idling?
Can you restart it right away?

These ECU's are not known to fail. Hardly ever have we seen fails in the ECU and most were related to massive electrical problems (shorts and inverted polarity by hooking up the battery the wrong way.

 

Today we threw parts at it.. New distributor, rotor . cap, module. We didn't put a new coil in as the one we have is less than 10k old. Runs good but we're staying close to home for a while. Lets face it this old puppy has 310k on the clock. So the parts probably needed to be replaced anyway. We have the fuel pressure gauge hooked up so we can keep an eye on the pump and maybe the circuit.

To answer the questions: The first stall happened at a stop light and the second happened while doing about 45mph. Does it restart right away? : from idle, yes it started, but it took longer to start. From driving, no it didn't restart until about 30 minutes later (you know , when the tow truck showed up).

Thanks for the come back.

 

Hop that fixes it. We have seen the ignition modules go out this way on these engines. Fingers crossed.