[fatdaddy62]

Eric I had this exact problem with 2wd 4.3L 1991 and I replaced many parts including the fuel filter, Pump, and tested coild take it out for the run and make sure you have fire when it breaksdown. If you do then I would suggest the Throttle Position Sensor and IAC. These two replaced at one time fixed my problem which was to drive out and after operating temp it just shuts down and spins. Let it cool off and it runs perfect.
Good luck,