My son has an 89 S10 with a 4.3L engine. Ran fine until recently. After a 4 hour road trip it stalled but he was able to get it started after about a ten minute rest. The next day it stalled about a mile from home and he was able to get it started after it cooled down for about an hour. Later that day it stalled again just down the block. We pushed it home and now it sits. It will start and idle for about 5 minutes and then it stalls. Thought it might be the fuel filter - changed that - same thing. Any thoughts?

 

Start it and let it stall then turn the key on and check if the fuel pump is passing fuel. It may be overheating then shutting down.

 

it may be the ignition modual, if it's getting fuel. you can have the tested usually at major parts stores

 

It might be losing a cylinder after warming up - no spark/electric/etc...

 

Check your fuel pump relay. It could be like was already said about a module. It could be overheating and shutting down.
You may want to check the regulator on the throttle body. Although it dosen't sound like your problem.
Good Luck