1996 Chevy Blazer stalls after 4 hours cools 10 minutes sta

I have had it stall while I was driving 3 different times and the last time was in an intersection. So when they test it now they let it sit and it will stall after 4 hours of running. It will restart after about 10 minutes from the stalling. Fuel pump and filter changed in June 2008, then all my problems started. They then changed the pick up coil, crank sensor and vapor tested and changed the computer. Those are not the problem. Everyone is stumped even the GM dealer here. Engine is good and transmission is good and the body is good. Would like to know what to try next. Getting expensive to fix. Any help is appreciated.

Well trying to restart it they tested the fuel pressure and it is fine. I just had a tune up and they said something about it has spark. As for the injector they said it isn't that. I had to go to the garage and ask. When it died the last time and the person who pushed me out of the intersection said it sounded like my fuel pump or battery. Both tested fine. Everyone is stumped. Ugh! I really like this vehicle but at my wits end.

The spark is there. The pick up coil was tested and replaced. Not sure about the ignition module will have to ask. I also had a complete tune up at the same time as they have been testing everything and trying. Anything Else I should ask while I am asking about the Ignition module? Thanks for all your help I am very appreciative with any information or things to try.