Truck Repair: 1989 gmc 1500 4x4, oil pressure switch, crank sensor

Question
when truck warms up it quits - no fuel --cools down for about a half hour and it starts and runs again till it warms up and stalls--new fuel pump-ecm-pump relay coil distributor-cap -wires-water temp.unit-no change what-so ever!when not running fuel pump will not run -wtars great except right after it stalls-runs great except when stalls fuel gauge worked before pump change not now -cleaned all grounds and gauge worked for an hour then doesn't work - had same problem with stalling before pump change  

Answer
Crank sensor comes to mind, although there is an oil pressure switch that supplies power to the fuel pump as long as there is 4 PSI of oil pressure, so the pump should be running.
I am thinking the crank sensor isn't sending a signal, and the injectors are not getting pulses.
It is in the distributor I believe on your engine.
www.autozone.com has a component locator page....free , as well as repair info.

Van