89 4X4 stalls when warm

My buddy's 89 454 stalls while he's running down the highway. I've done the usual checks including a code check. I can't find any problems. When it stalls, no fuel comes out of the throttle body. If it sits for a couple hours, it starts working again. It may run good for a few weeks, or a few days, then BAM...stalls out again. Plenty of fuel in the tank. Filters are new. I am gonna test his fuel pressure today. Any other ideas?? Heat sensor maybe? Oh yeah, it seems to be happening more frequently as times goes on.

Thanks in advance

Most likely fuel pump, but could be fuel pump relay or oil pressure switch--There is a electrical circut to shut off fuel when oil pressure drops to save engine -if oil pressure switch is bad could send computer no pressure signal shutting off fuel--also 88-89 had two oil pressure switches usually--one for comp. by distributer and one on drivers side engine.

Thanks mbumgua, that makes perfect sense. I didn't know there were two oil pressure senders. Fuel pump pumps like hell, but something is shutting it down. I'll check the switches. Thanks again

Check your ignition wires for worn insalation This would cause the wires to short out when the engine gets hot thus no compustion would happen

There's no fuel coming out of the injectors, therefore no combustion. It was the engine saver shut off. Thanks again

Glad you got it figured out Smokee.