Hello all,

My '89 Turbo wagon has been having this weird jumpy idle, accompanied by a equally jumpy tach, and frequent dieing at idle. When driving, the problem is characterized by a periodic yet extreme stumble which can slow the car to a crawl before it recovers or again, just plain dies. So, I thought it might be the Hall sensor, but nope, the previous owner had the distributor replaced with a completely new unit. I took it off just to be sure and yep, everything looked new. Now I don't have a multimeter so I got out my old Sears induction timing light and clamped the pick-up lead around the coil wire and had my helper hold the trigger down on the timing light while I cranked the engine. The tach was jumping but the light did not flash. However as I continued to crank the light came on periodically indicating a sporadic spark coming from the coil and then when the car finally fired up the light became the steady strobe effect you would expect if the coil was working properly. I kept the timing light on for several minutes and observed the light blinking out a few times until the car finally stopped running as it always seems to do. So, is this the ignition module or could it be something else like the radio suppression relay, or knock sensor? Could it even be the coil itself? Any help appreciated. Sorry about being so long-winded.

Matt Campbell
'89 740 Turbo wagon