92 Boneville 3.8 SE engine cuts off after 10min of running

Hello,
I'm new to this forum, i went through other posts and i couldnt find an answer to my problem. I have 92 Pontiac Boneville (3.8L)with an attitude...
I starts up ok, runs for around 5-10min, perfectly, no mises, then sudenly shuts off the engine. When trying to start up the engine again, engine cranks but doesnt start, no spark on spark plugs or fuel injection(removed fuel injector), i have to wait for 3 hours minimum to start it up again. It starts up fine runs for 5-10 min and shuts off again... Our first step was to check for fuel pressure, it holds steady at 40psi. Next we checked the spark on the plugs, there was none, so we went and got new ignition module and coils (type 1). Started up the engine, 10 min later same story...I checked the RAP/IGN relay by swapping with another one, same story....Checked the PCM for stored codes, but found nothing and it seems to be running ok(compared values with the one in service manual)...Our next step is to get new PCM. Is there anything else i can try before getting new PCM?
Thanks for all responses.

Have a scanner handy when this happens, check for cranking rpms when it won't start, if none, suspect the crank sensor or wiring to the icm from the sensor.

Hello,
I'm new to this forum, i went through other posts and i couldnt find an answer to my problem. I have 92 Pontiac Boneville (3.8L)with an attitude...
I starts up ok, runs for around 5-10min, perfectly, no mises, then sudenly shuts off the engine. When trying to start up the engine again, engine cranks but doesnt start, no spark on spark plugs or fuel injection(removed fuel injector), i have to wait for 3 hours minimum to start it up again. It starts up fine runs for 5-10 min and shuts off again... Our first step was to check for fuel pressure, it holds steady at 40psi. Next we checked the spark on the plugs, there was none, so we went and got new ignition module and coils (type 1). Started up the engine, 10 min later same story...I checked the RAP/IGN relay by swapping with another one, same story....Checked the PCM for stored codes, but found nothing and it seems to be running ok(compared values with the one in service manual)...Our next step is to get new PCM. Is there anything else i can try before getting new PCM?
Thanks for all responses.

Usually when an engine cuts off and does not have spark or injector pulse, I suspect the CKP sensor is the cause.
Do this test

connect a fused jumper between the sensor positive voltage circuit at the ignition control module harness connector and B+.
Connect a second jumper between the sensor ground circuit at the ignition control module harness connector and engine ground.
Connect a Digital Multimeter to measure voltage between the CKP sync signal circuit at the ignition control module harness connector and B+.
Observe voltage while cranking the starter.
Is the voltage between the specified values of 1-3 V?
If so the CKP sensor is good,
if not Check the following crankshaft position sensor circuits:
- The CKP sync signal circuit for an open or short to voltage.

- The sensor ground circuit for an open.

- The sensor positive voltage circuit for an open or short to ground (including camshaft position sensor shorted )
if the circuits are good, replace the CKP

Hi,
It was CKP sensor, 18x loop, we replaced it and ran the car for an hour, engine didnt shut off. BIG thank you guys for your suggestions.

I had the exact same problem with my 92 SSEI. It was the crankshaft position sensor. It had a crack in it that allowed it to lose integrity once it warmed up.