my 1993 silverado pu will not start after it reaches operating temps

I would start by verifying the fuel pressure, it should be 9 to 12 lbs. , 15 lbs. at a dead head check. Also may be dirty or bad injectors, they are hard to clean manually other than running a injection cleaner threw the gas...When you start the truck, have the air cleaner off and look at the 2 injectors to see if they have a nice cone shape of spray with no droplets of gas. Another cause would be that the regulator in the TBI is weak. There are rebuild kits for them. Thats why check fuel pressure while running, and at a dead head check.