I have a 1991 940 turbo wagon that has begun to falter and die intermittently. Recently I was driving and the engine/power falterd and eventually stalled. I got it restarted a couple times but it would die shortly after being put in gear. The car was towed to my mechanic the next morning where it started and drove fine. He couldn't find anything wrong with it. The diagnostic computers showed nothing wrong. It drove beautifully after that. Several times since it has faltered, driven haltingly with the RPM dial fluctuating wildly but not stalled. This condition lasts for .5 to 2 minutes tops and then is fine. I noticed hitting potholes or bumps could bring this on. Today, I drove over a speed bump and the car cut out and died completely. (It is perfectly clear, sunny and about 50 degrees. I had thought that it might be moisture related, but not today.) I restarted it with no problem and it drove for another couple of miles and then it faltered and stalled. I restarted it several times by flooring it to really rev up the engine. It would then drive fine for about a half mile (or less) at a time before stalling again. Finally, it completely died and was unstartable. My mechanics are stumped. Any ideas?