91 LeSabre cuts out after warm up

Hi everyone, thanks for reading...

My 91 LeSabre (3800 engine) cuts out after warm up. Some times after Ive driven a few miles, and some times after warm up in my drive way. When I try to restart, the engine just cranks and cranks, and the over temp light stays on along with the check engine light. Upon cool down it starts right up on the first crank and all trouble lights are out. The coolant does not boil over, I don't think it gets that hot. I've replaced the thermostat (old one was ok), I can feel the coolant being pumped (think water pump is ok, some stains from sepage below the pump), Ive replaced the ignition coil and the ignition control module (old control module had melted its "goo" out), cooling fan works at both speeds, Ive replaced the two wire coolant temperature sensor that send info to fan for high or low speed, Ive purchased the cooland temperature sending unit (one wire), but can't find it on the engine to replace it!! Ive also replaced the radiator cap. The cam sensor magnet, timing chain, and electronic air conditioning and heating in dash controler unit have just been replaced by the dealer (no probelm with cutting out before this trip to the shop). The car has 90k miles.

Thanks for any help you can give!! This is driving me Crazy!!!!

See if you have spark and injector pulse when it won't start, if neither suspect crank sensor or wiring from sensor to icm