I don't drive my 1988 560SL a lot but yesterday jumped on the freeway with it. After about 15 minutes on the freeway the car suddenly lost all power. I went from 70 MPH to 50MPH with the pedel to the floor. I got off the freeway and couldn't even get the car up to 25MPH. Everytime I would start the car just wouldn't go. I parked it for about an hour thinking I was going to have to have it towed home and when it cooled off it was prefect again. Then about 1/2 home it started the same thing. It seems fine until about 20-30 minutes of driving. The one thing I discovered on the way home was if I pushed the pedel all the way to the floor it would suddenly take off flying again.