It's always something.... A couple months back, when diagnosing a surging problem I just can't seem to nail down, I swapped a known good distributor in, and it made no difference. I put my original distributor back in, set the timing, and called it a day. Upon firing it up, the truck would not idle at all. It would start, run for a few seconds, and then die. I've installed a new fuel filter, IAC, checked the fuel pressure, checked and re-checked the timing, TPS adjustment, Temp Sending Unit, MAP sensor, EGR system and vaccum, and I'm at a loss. I've turned the idle up so it won't stall when in Park, but I need to keep my foot on the gas when in Drive to keep it running at a red light. Other things of note: -The truck will stay running when the timing connector (sorry, forgot the technical term) is disconnected, but obviously it's a dog driving it like that, due to no timing advance. When I hook the connector back up, it returns to stalling as described above. -I attempted to check the idle speed using the tach lead off the coil, and it doesn't seem to be working correctly. On my meter, it reads 120 RPM, and when I blip the throttle open, the value goes down instead of up. I checked the meter on another car with no known issues, and it worked fine on that one. -None of this ever happened before I swapped distributors. 1987 Burb, 350 TBI, engine and trans are bone stock. Thanks in advance for any help!