Cadillac Repair: 1992 cadillac eldorado, throttle position sensor, cadillac eldorado

Question
Hello,
My niece (single mother with two children) recently purchased a 1992 Cadillac Eldorado Coupe (4.9 Liter) with 134,000 miles on it. The car recently began stalling (dying) at random intervals. Usually it will restart after 30-90 seconds. We have spent a small fortune in taking the car to dealerships and after-market auto repair services to no avail. When the engine stalls the engine cooling fan starts running immediately regardless of engine temperature. The car experiences strange surges from the transmission when driving at low and highway speeds as if the torque converter is "locking-unlocking". If the engine is above 2,000 RPM the engine usually does not completely stop but falters for a few seconds and continues running but when operating at an idle or driving at slow speeds it stops. The engine temperature reaches 220 degrees during slow driving or when climbing steep hills but does not exceed the GM owners manual of the maximum allowed 240 degrees. The fuel pump assembly, alternator, battery, throttle position sensor, ignition coil, spark plugs, spark plug wires, distributor cap, rotor, and fuel filter are all new. I have read numerous accounts on the internet from other 92 Cadillac Eldorado owners of this model year that have similar issues but no definite answers were given as to correcting the issues. Any ideas? I really need to get this car running and reliable for her and the kids ASAP.
Thanks,
Jim  

Answer
OK, Let's get this fixed once and for all.

Perform this simple procedure.

1. Turn ignition ON, Engine OFF.

2. Simultaneously push and Hold the OFF and WARMER buttons on the climate control panel until all the segments in the display illiminate and then release the buttons.

3. Write down ALL the NUMBER/LETTER combinations that appear on the screen until it stops and displays either ECM? or PCM? and let me know which appears ECM or PCM.

4. Let me know EXACTLY how the NUMBER/LETTER combinations displayed.

5. When your done writing down the NUMBER/LETTER combinations if the ECM displayed in step # 3 push the RESET button.

6. If the PCM? displayed in step # 3 push the AUTO button.

7. Turn OFF the ignition.

8. If you miss any numbers just repeat the same sequence as above.