I have a 2001 Express 1500. I got it cheap with over 300k miles. The previous owner has replaced the distributor cap, wires, and plugs. I've been surprised with its reliability so far but lately it's shutdown on me while driving multiple times now. It starts up immediately while coasting in neutral. This only seems to occur after running at operating temperature for some time. I come back the next morning and it starts without hesitation. If I only run I for a quick errand I have no issues. I've replaced the fuel filter and the fuel pressure test is within range. The engine codes previously stated P0300 (multiple cylinder misfire). Since replacing the fuel filter and resetting the pcm/ecu the service engine light hasn't shown up until moments before shutdown. The idle will choke up and the throttle gives no acceleration making the shutdown predictable enough. A friend suggested the fuel pump is overheating. I've flushed the engine at my last oil change and run multiple fuel system cleaners. My next step is compression tests but I'm curious if anyone has any insight on this circumstance and can provide a wise diagnostic approach to deduce the proper repairs.

 

could be a janky ignition switch

 

If it has an ICM in the distributor these do a great job of intermittent failure when hot. Drove my 93 Sub with your symptoms for 6 months before it quit for good