The subject of this bizarre ailment is a 1986 740GLE non-turbo wagon with approx 260K miles. No recent problems until the engine stalled while going uphill, then wouldn't restart. While trying to figure out what was wrong, I wiggled the coil wires and the wire going to the sensor adjacent to the air filter. Car eventually started after much cranking. During the drive home, I noticed that the engine would stumble/miss at each sharp bump in the road at freeway speed. Took the car to the shop where it was diagnosed as a failure in the in-tank fuel pump (which I had replaced about a year earlier, along with the in-line booster pump). I haven't had the car stall enitrely since, but the misfire when hitting a bump remains, and I noticed that the tach drops to zero each time it misfires...it sometimes cuts out for a split second, sometimes for a couple of seconds, and only seems to happen at higher speeds or under load. I figured it might be caused by the wires I wiggled, so I removed them, cleaned with contact cleaner, and replaced. I still have the same problem, which cannot be replicated at idle. Any ideas on how to troubleshoot this problem? Thanks for your assistance...

-Kevin, Santa Cruz, CA