I'm currently overseas, but a friend emailed me with what sounds like either a failing ignition module or RPM sensor. I'm not familiar with 850's, having worked only on 100, 200, and 700's, the most recent of which is my '90 740 w/ Regina. She reports the engine suddenly stopped without sputtering or missing last week at highway speed, but restarted within a few minutes. Since then, it's happened twice more on sidestreets, and once on the interstate, all followed by restarts. She doesn't report what the tach was doing upon failure. Alternate diagnoses are 1) a failing fuel pump relay, presuming 850 relays had the same solder problems as earlier cars, 2) main fuel pump failure, and 3) injector relay failure. If it's an 850 turbo, does that mean a Bosch two-pump system? Do 850's also have the same injector relay/radio supressor relay pair as the 700's? Thanks everybody.