Driving the other day in my 1988 780 Bertone with a V6 B280 it stalled at a traffic light and now it won’t start. I’d been driving for about five minutes and the car was running fine except for a little sputter and hesitation at the previous traffic light.

Reading through FAQ it appears troubleshooting is similar to the B230. Here’s what I’ve done:
1. Replaced Noise Suppression Relay.
2. Replaced Fuel Pump Relay.
3. Verified 12V across plus and minus wires at main fuel pump when cranking. Didn’t see a quick voltage jump to 12V for priming when key first turned to position two. Maybe it happens too quickly.
4. Disconnected fuel supply hose at rail and turned key - gas did flow from hose.
5. Pulled plug wire and attached paper clip, turned key and verified spark to metal.
6. Pulled injector connector and measured 12V to ground from each pin when key turned to position two and 0V from pin to pin. When cranking motor, pin to ground voltage varies slightly from 12V. I’m assuming 12V is applied to each pin (injector closed) when key in position two and one pin rapidly changes from 12V to 0V (from ECU) to open and close injector when key in position three. Maybe too fast to see on DVOM.

Any suggestion on what to do?


Thanks for any help,
Michael
Melbourne, Fla

1985 740 470k
1988 780 Coupe V6 199k
1992 745 210k