I've got a 1995 jeep wrangler YJ, 4.0L straight 6.
The first week of july i was driving through town on an extra hot day, 30+ degrees. At a stop light the jeep started bucking violently as i began to drive, i pulled over and the jeep stalled. Since then the jeep starts fine when the engine is cool, it will run until it reaches normal temperature then the bucking begins, the rodeo lasts a few minutes and the engine stalls, the jeep will not start again until the engine has cooled. During the bucking the RPM's drop and pick up again, its a continuing fluctuation. It only behaves like this when the engine gets to temperature but according to the gauge the engine isnt overheating. We had it at a garage where they replaced the computer and the Crank position sensor, they had it hooked up and said the jeep is showing no codes, and there is no engine light during or after the vehicle stalls.
We have replaced:
spark plugs, filters (air, oil, fuel), fuel pump, throttle position sensor, crank position sensor, the computer, manifold absolute pressure sensor, thermostat, idle air control valve, and the ignition coil. (in that order)
Nothing so far has worked, please help!!