Randomly shuts off, then restarts after it sits for an hour or 2?

[Super_chevy]

This happened to me after I put in the 383 turns out my motor starter was getting over heated and the truck would shut off then wouldn’t start up until the starter cooled back down. Flush my coolant and refilled found out shop filled it up with straight water no bueno with these trucks has to be dextrose no issues after that

Also had a high torque starter

 

[Jerryf6368]

I had the same issue & it was the Ignition Switch Wiring Harness. Easy to switch out, just buy a good Harness not the cheap ones.

 

[tomb]

With any intermittent problem the worst consequence is to your confidence in the truck. Be prepared for the next unscheduled stop. Research the pins to verify crank signal, see now what a proper crank signal looks like. Does the system have a cam sensor? Know that circuit too. Is there a check out procedure for the ignition module? Take notes so you are prepared to act quickly when the trouble presents itself. Do you have the specialized tools to back pin the ecm connector? Develope a plan to do all of these checks quickly.
Another way to look at the problem. How much does OEM crank, cam & ignition modules cost? I had this issue on a son-in-law's jeep. His had three sensors which only cost $80. I changed all three and it never died again.
Intermittent problems are the worst and are best solved with detailed system knowledge. I'm not a fan of the parts cannon unless the cost benefit provide both troubleshooting results and refresh of high failure or consumables parts.
If the components don't resolve the issue, wiring is suspect. I chased a bad CTS circuit for 6 months only to find a pin slightly backed out of the connector. Make sure all pins are seated and are locked correctly in the connector housing.
I hope you already found your issue.
Good luck!

 

[Hell Knight Hicks]

Dunno if anybody has mentioned this but check the oil pressure sending unit on the back of the motor there next to the distributor.

Thats what determines power to the fuel pump after start up.

 

[Schurkey]

Dunno if anybody has mentioned this but check the oil pressure sending unit on the back of the motor there next to the distributor.

Thats what determines power to the fuel pump after start up.

That...in combination with the fuel pump relay. EITHER ONE will power the fuel pump.

 

[SUBURBAN5]

Also had a high torque starter

What kind of starter is that?

 

[Super_chevy]

It just spins faster than a normal starter, however the problem would be the same if you have a stock motor and stock starter when the truck shuts off see how hot the motor is, by actually feeling the heat coming off not the gauge

 

[CrustyJunker]

Interesting find, glad you got it fixed!

 

[Kens1990K2500]

That...in combination with the fuel pump relay. EITHER ONE will power the fuel pump.

I'm a bit confused ... so can either one independently power the fuel pump? Or does power need to go through both the relay and oil pressure switch, before operating the fuel pump?

 

[Kens1990K2500]

I pulled our camper back to the Oklahoma sand dunes today. The truck ran great again. All seems back to normal.

Thanks for all of the ideas and help. Next time this happens, I will be better prepared on how to attack the problem.

Glad to hear you're back on the road again. I've been following this thread, and I started a similar thread around the same time, for the same issue. I have borrowed a relative's car and use that 95 percent of the time. I try to drive my truck once a week so it doesn't sit too long, and it has not acted up since the day it failed to start at work. Once the weather warms up a bit, I will be checking the engine grounds, and replacing the ignition control module, and possibly the distributor pick-up coil. I already replaced the ignition coil about a year ago, prior to this problem.