So,since my last post, I've actually been able to recreate this problem under certain conditions. This is what I'm experiencing with my sons's 1990 240 Turbo Sedan.

1. Twice, heading down the road, at about 50 mph, the car suddenly lost power and then stalled. I fiddled around with it a bit, jiggled the wiring harness near the CPS and it started up again. Ran fine the rest of the way home.

2. Several times, usually in the morning, the car will turn over but not fire. Then it will fire, but sputter and then die when I put it into drive. Once, I put pressure on the wires connected to the Fuel Pump Relay and it started again immediately. After a few minutes, it becomes normal and drives perfectly.

I can generally feel the relay clicking. I know its not the crankshaft sensor (I've replaced it twice with OEM parts). I can hear the fuel pumps buzz when I jump fuses 4 and 6. I've replaced the 25A fuse under the hood.

Could it be the female connector to the relay, maybe? The ECU, itself? The entire harness? Any thoughts. It feels electrical to me. The times when I've been able to fix it roadside or in the drive, I've basically just moved wiring around, or reconnected the relay, or put a little pressure on the wires by the relay connector. But each time I think I've isolated the area, I try to adjust it and it doesn't take.