Cadillac: cadillac Repair, throttle position sensor, fuel pressure regulator

Question
I own a 1991 Eldorado with 115k miles. It runs fine for about one hour and then it developes a rough idle and hesitates on acceleration. I live in the desert and it runs rough when it gets extremely hot.It isnt losing antifreeze. Any info would be useful.
Paul

Answer
it could be anything from a heat sensitive:

Fuel pump.

ignition module.

TPS (Throttle Position Sensor). Does NOT always turn ON the check engine light.

spark plug wires.

ignition coil.

fuel pressure regulator.

Could also be a leak in the intake manifold gasket once the engine gets warm and the gasket gets hot.

There are many more possibilities.