I have an 86 GN, and when I first take off/at stop lights some times, the car starts getting a little rough and the rpms come down to 500rpms (I idle at 1000) and when I put it into gear for the first time, sometimes they will drop so low it dies. I turned up the fuel pressure about a # or 2 thinking it was lean. nothing. Changed the plug wires. nothing. changed fuel filter. nothing. To give some background, my turbo's seal is worn and blowing oil through the intercooler right into the cylinders(bu this started after the blowthrough-out of no where one day it started running rougher). Any ideas?
TCC solenoid. If that switch starts to stick, it will cause your car to stall when you come to a stop. The car will even "buck" when you take off at a moderate rate. According to your staements above, I would certainly suspect the Torque Converter Clutch Solenoid. You will have to remove the transmission pan, but this would be a good time to change the fluid and filter.