1992 Dodge Caravan, jolts intermittenly

I just bought a 1992 Dodge Caravan. I have only had it for 2 days. I will be driving and then there is a jolt. It only happens ever so often. This has happened at 20 MPH and 60 MPH. Another time it happend at 25 MPH and the car died. Still coasting, I put it in neutral and turned the key, it started fine and I went on my way. Doing research, could it be the auto shutdown relay? What do you think?