1992 Dodge Truck

Well this could involve a very broad range of problems from overheating to electrical. Try an OBD1 scan tool if you don't know where else to start. Are the guage readings normal, temperature and oil pressure? Does it idle rough or perfectly fine. You may find your auto-shutdown relay a suspect.

seems to idle fine, have had the truck to two mechanics and to a dode deaership and they say they can not igure it out. I need help

Well do you know where those items are on the truck? Does it overheat or does the oil pressure guage have a normal reading? Does it just turn off unexpectedly and abruptly with no apparent symptoms or does it sputter and stall? Same idea applies I couldnt tell you where to start, electrical most likely, but it could be a small crack or fissure on the intake manifold that opens when the engine becomes hot. Did the mechanics say anything whatsoever?