I picked my '91 XJ up from the shop yesterday for overheating and it started up great and ran great until it got to where it needed to shift to second. It just wouldn't shift. The engine would just rotate faster and faster and it wouldn't shift. I even tried to shift it manually but it had no effect. I limped home going about 20 so I didnt strain the engine too much. My fluid is full so I was going to take it to a trans shop today, but as I was leaving the neighborhood, it stalled three times and now it won't stay started. I also can't shift into reverse or park now. What is going in. Someone please please help me.