I have a TPI 383 stroker in my 1988 k1500. My father built the engine years ago. Recently as I have been restoring the truck, the engine has developed a habit of shutting off randomly at idle, and occasionally sputtering during driving. It has a mildly spasmodic idle at times. Sometimes, the truck won't start AT ALL. When it dies at idle, it will not start back up without me messing with wires under the hood. IE: coil wires, plug wires, ICM wires ext... eventually, it will start again, but dies after 2 minutes of idle. I have replaced the Coil, and ICM in the distributor, and cleaned the IAC in hopes of fixing the problem, even added a bigger air filter. Nothing helped. I can't be sure if it's the fuel system, because I can hear the pump running to prime the system upon turning the key. The filter hasn't been replace for over 10 years(it sat for those years) But I have reason to believe it is loosing spark as my friend told me he checked it once when it died at his house, and it had no spark. I've been at this for months. Please, anything you can say might help!

 

Check your fuel presure and the grounds to your fuel pump, a ground but not real good will run the pump but not at full speed so it does not maintain proper pressure

 

I checked the grounds and found the tank ground strap was loose and corroded. fixed that and it idled better. But still stalled. then i OHMs tested my pick-up coil and it was fine at 786 consistently. Then i took out my new ICM and put an old one i found laying around in it. started right up and hasnt stalled since. Thanks for your help!!