My '94 Alty has 193K miles, is clean, good paint, no rust, etc, and in very good shape overall, but has recently developed a bad problem. It began about 5 months ago when the engine started cutting off as I was driving at highway speed and after a couple of miles it quit and the battery wouldn't turn over the engine. I got a ride home and came back with a battery out of my truck and it started and ran fine to a shop I use about 10 miles away. They checked it out and said the alternator was bad and replaced it with a NAPA rebuilt. Then a month or so ago it did the same thing only at night 35 miles from home. I had it towed to the same shop. They said the alternator checked out good but the battery was bad and put in a new one. A week later same thing, engine cut off on interstate highway 70 miles from home and wouldn't restart. I had a battery in the trunk that I had taken out of my truck just in case and when I put it in the car started and ran good all the way back home where I recharged the new battery. Then a week later it quit again 5 miles from home and the new battery was dead again. It had a new, not rebuilt, distributor put in about 1-1/2 years ago and the shop now says everything electrical and electronic checks out OK on their SUN diagnostic machine and they don't know what's wrong. Another mechanic I talked to said the ecu computer could be bad and the SUN machine wouldn't show it. Does that sound reasonable? I can get a remanufactured ecu installed for about $300 but I'm now wondering if that doesn't fix it is worth it to keep on trying to find the problem by eliminating one possible cause at a time. I ran a for sale ad on Craig's list telling about the problem and was offered $500 by a guy who wants it for parts. I haven't taken the offer yet but I am tempted.