Pontiac Repair: enginecuts off, gm cars, abs brakes

Question
I have a 92 Pont Sunbird, 2.0 ltr, 4 cyl,about 200,000, with about 40,000 on new motor.  it has AT, PS, AC, CC. It is fuel injected, with ABS brakes and rack and pinion steering.  Recently changed ignition control modual, oxygen sensor and a full tune up.  
Now the problem....after driving for several miles, when I have to stop at light/sign the engine cuts off.  It will restart, but when put in gear will cut off again.  After about 20 min, it will start and run but after about 20 miles and having to stop, it cuts off again. Any ideas?

Answer
Sounds like the transmission needs a fluid flush and filter replacement. When you come to a stop after driving for 20 minutes does the car feel like it wants to keep going? If you have ever driven a standard shift it would be the equivalent of trying to stop without pushing in the clutch. If this is what is happening the have the above services performed. What is happening is the torque converter in the tranny is getting stuck in lockup and lugging down the motor when you stop. This is actually very common with GM cars and the reason for the flush is to remove all the old trans fluid, changing the filter only gets about 1/3 of it. If this doesn't correct the problem then you may need to have a tranny shop replace the lockup solenoid or if this isn't what your symptoms are then you are loosing fuel or spark. Let me know if this doen't match what you are experiencing and if so try to provide a little more of what is exactly happening and I'll try to help.