My 1996 CHEVY BLAZER 4.3 will start run fine till it reaches running temperature then just dies if I let it cool all the way off it will run about the same time 15 min then die if I try to start it again directly after it won't start just turn over

starter bushings going bad. replace bushings if you can, replace starter otherwise.

Trail Blazer has a very cool 'plastic' intake on the Vortex series. I would have the intake checked out, or just replace it with a new one. Don't reccomend a used one since it was a common problem.

sounds like your coil is getting hot then when it cools down the engine re starts check coil look for hot spot or touch it see if it is hot it should be cold.

If you have Code 15, you need a volt meter or you will run into a wall. You measure the coolant resistor ohms when its cold then measure it when the engine is warm.You also have to measure one side for a 5 volt reference.Or better yet when the vehicle reaches operating temperature and begins to stall take the leads of the coolant temperature and jump it together.This tell the ECM your temperature is 266F. If its stays running and doest stall replace temp sensor

I have a 96 2wd chevy Blazer runs fine till i get about a mile or so up the road and then shuts down when i brake at stop sighns please help

Does the fuel line still have 55 PSI when engine warmed up? Any other codes show up?

I WOULD STILL CHECK THE FUEL PRESSURE.IF ALL IS GOOD.ENGINE GETTING TOO HOT WILL SHUT OFF.ALSO A LEAKING INTAKE GASKET WILL CAUSE STALLING WHEN HOT.

swng,
1) Is the service engine soon light ever on when engine is running?
2) Per your description I would look at the ECT sending unit. It sends coolant temperature information the the Engine Control Module for proper fuel delivery for cold engine start. It may have lost its calibration.
Let me know.
Regards,

Replace the coil packs.....

No I haven't fixed the problem yet but don't think I want to pay not knowing whether or not anyone can help me. Thanks anyway.