Recently bought an '87 744 that ran (with several re-starts) under its own steam the few blocks to my house. Can't road test it - on blocks awaiting major surgery (rust, brakes, exhaust). However, have had a chance to work on the "stalling" problem. Would start fairly easily, idle very nicely, run for 1 or 2 or 3 minutes, then die. Tachometer needle always fell like a brick upon stalling. Fuel pump continued to run for 1 or 2 seconds after stalling. Took cover off fuel pump relay. Pressing contacts made both pumps run. Idle air control motor hummed normally. Sounds like ignition. Replace coil, cap, rotor, wires, plugs. No change. Install rebuilt distributor with new Hall sensor. No change. So then took a new tack that I should have done right off. Stuck a screwdriver in accel. linkage to make it rev at 1500. Ran smoothly for 5 minutes, 10, 20, 30 ... forever. So it's getting steady ignition and steady fuel: always was. HELLO -- It wasn't a running problem, it was an idling problem. Took the idle air control motor apart - not very dirty, but when cleaned and re-assembled (you wouldn't want to watch, involved Dremel cut-off wheel and duct tape) it will now idle smoothly forever. (By the way, also accidentally found the grounding terminal behind the air filter box, on the left fender sheet metal. It had mucho white corrosion product on the inner contact surfaces. Sanded it away and added silicone di-electric stuff).
Moral of the story: (1) I will now put less faith in the old adage, "Instantly dropping tach needle indicates ignition problem." (2) Stalling from an 800 RPM idle is a totally different situation than stalling from 1500. (3) It might have just been the corroded ground all the time?
Andy Crosby
'85 244, '87 744