Chevrolet Repair: intermittent stalling, service engine soon light, fuel pressure

Question
Jim I hope that you can help me. I have a 1993 Z-28 Camaro with a six speed and 200,000 miles on it. It was running fine untill a few weeks ago when an intermittent stalling problem started. I can be driving along at any speed and the service engine light comes on, the tach drops to zero and the car stalls. It doesn't restart before ten or fifteen minutes. Then it can run fine for days before it happens again. Last night I was leaving a parking lot about ten miles per hour when the light came on, the tach read zero and the car stalled. I pulled over and tried to restart it but the service engine soon light stayed on the engine cranked and I smelled gas. But it did not start. I waited about ten minutes and tried again. It started right up and I drove the car home with no problem. This morning I was driving about 45 miles per hour and the service engine soon light can on the tach read zero and the car was slowing. I kept the car in gear and as I was coasting the car bucked and started up. A few seconds later it did this again and restarted and stayed started so I was able to make it in to work with no other repeat. I have had the car into two shops and of course the problem doesn't happen for them and they give me the car back saying they can't find anything wrong. They checked fuel pressure which is fine and they only said the computer had a soft code 16 in memory. Can you please help ?  

Answer
 Hello Roy,
It sounds like a bad wire,, if the tach gos to 0 rpm and
the engin is still turning over ( buy the wheels turning)
some where your losing power to the ECM. I wont be much
help, but there is where I think your problem is.
    thanks
      Jim