1995 Jeep Grand Cherokee shits off while running then after some minutes turns on like nothing happen .

You're on the right track. The crank case position sensor (on bell housing, aimed at flywheel) is a common failure on that engine and it does exactly what you described. It's kind enough to cool down and let you get home. It stalls from lack of spark and will show a code P0320. Code P0340 would be camshaft position sensor. Acts the same but less common a failure.