Is the clue in the observation that it was as if you had turned off the ignition? I puzzled for three weeks over a similar occurrence until those words came back to me and I replaced both fuel and IGNITION relays.
The other time I had the lane crossing experience at 80mph was a puzzle too: the power would drop to 1500rpm and then restart without problem until a steady speed (80+) was reached and the same thing would happen. Turned out to be the alternator. I changed that and it has not happened since. Just a thought.

Last edited by meabh; 30/09/14 07:47 AM.