1991 Olds 88 shuts down when hot, won't start when hot

'91 Olds 88 will shut down after about 25, 30 minutes of driving. On short trips (under 25 min.) it won't start untill it cools off (about 20, 25 min).
I have replaced the coil and module under it. The module was all melted inside, not burned, just melted, whatever that plastic like stuff is. Also replaced the temp. sensor to the computer. I've been told the next possibilities would be the crankshaft sensor, or the camshaft sensor, with the crankshaft sensor being the most likely, and hardest to change. Any with an idea...?
The only code I get is 43, knock sensor. I don't see how that might cause this though.

Welcome to AF. Check for spark when this happens if none suspect the crank sensor, very common.

not sure this willl help but had a similar problem with my 97 down on the drivers side floor there is a wiring harness and some of the grounds are ganged together if one gets hot it will affect the others i cut the wires and added new ends grounded them together and havent had a problem since

Correct on the gd junction this will kill the fuel pump.

found this affected a draw on the power windows which would want to make the car cut out ....let it sit for an hour and i was good for awhile ...good luck

Thanks to all. It WAS the crankshaft sensor after all.