engine dies under load

1990 4.0 it will idle very hi then back to normal ,but when i try to drive it it stalls out but will restart right away. i put on cps ,coil ,o2 tps,new fuel pump . fuel filter, you can rev the motor up and sometimes it acts like it gets out of time.!!!1

You say that it has a new TPS but is it adjusted correctly? That sounds like your problem to me. Search for the adjustment procedure and get a cheap digital multimeter. That will be your favorite diagnostic tool.

I've found way more problems with the connectors, the wiring, splices and grounds than I ever have with the sensors 5, 6 to 1 (Renix). I have an extra set of junkyard sensors for tests, but I almost invariably find the problem someplace else.
People act surprised when they replace a whole bunch of sensors and it still runs like crap, maybe someday they will catch on.
I guess I learned that lesson early, dealing with the mud and water I always seem to stumble into . I started out in 87 cleaning connectors, looking for chaffed wires and corroded grounds, funny I still have most of my original 87 sensors and most work fine.
I'd check the resistance in the ground circuit and clean the connector well before I adjusted the TPS.

Yeah, the Renix Jeeps seem to have a number of crimp connections buried in the wiring harness that get pretty corroded. I always check the ground side of the sensors and either trace the wire back or just add a new ground somewhere.