I have a 1988 745T with an engine out of a '91. This motor swap was done professoinally, about 50k miles ago, and I've owned the car for the last 5k of that - without any problems.


yesterday, on the highway (10 mins into a trip), the motor shut off at about 75mph. I didn't even really notice (i was off the gas anyway) until I got back on the gas - and nothing! I pulled over, waited about 1 minute then restarted and drove another 15mins home with no problem.

this morning, 6am, same thing happened, only I didn't pull off the highway. I was on a downhill, so I left the car in 5th gear (to keep engine spinning) and, still at about 70mph, started punching the side of the center dash/console area - around where the relays are hidden. The engine came right back on before the car lost any more speed.

I need to drive the thing for about an hour after work today to get home for holidays. Is there anything I should know? Any help would be greatly appreciated.

Observations: Both times I seemed to be off the gas when it happened,
Both times the car immediately lost power, but nothing on the instrument cluster (including the tach, i think) indicated a problem. Both times the car came back on moments later - problem never re-occured for remainder of trip.. Oh yeah, and each time, I've felt the relays - the second one in from the left on the first row of relays my hand gets to is always hot...

(the previous owner said he'd suspected a bad fuel pump relay - but he'd never mentioned this particular problem. I have a new relay in my posession, but who knows how old my current one is...)