I just want to clarify something nine months later..

My problem was not due to the fabled OVP relay. Rather I had an intermittant harness from the idle speed regulator to the connector block on the 4th intake runner. It took quite a while to find this as the problem would come and go, sometimes it went away for a couple of months at a time then I'd get a spate of cutouts, normally when the car was fully warmed up. I replaced the harness and the problem disappeared completely. I tested it by idling the car and wiggling the harness - bingo! I could never see open circuit with the multimeter which is weird.

Along the way I managed to replace the AFM due to a faulty potentiometer, that fixed a few flat spots etc.

Anyway thought I'd update this thread "for the archives"..