My 1998 did exactly the same thing, when it got hot it would shut off and not restart until it cooled down. My crankshaft sensor was bad, replaced it, and no further problems. It is located on top og the flywheel housing behind the engine right on top. It is pretty difficult to see and even harder to access, but if you hold your tounge just right, you can extract it and install the new sensor. I think I paid about 195.00 for the sensor.