I have a question of a generic nature pertaining to efi/tacho dash gauge.
The neighbour has a fairweather friend who has a habit of dumping his POS beemer 6 series coupe in the shed at the worst possible times. This time it was over christmas and the bitch would not start either so we had to push it around by hand.
Anyway, on the 'not starting' thing, the owner worked out there was no spark. I confirmed this with a timing light.
I also noticed that there was no tacho needle twitching when cranking the beast.
This had me thinking that maybe the ecu was not getting a crank angle reading, and not triggering the coil or the dash gauge.
Does this logic sound correct or does the tacho needle not moving, prove nothing????
If it wasn't such a cluttered engine bay I'd have attempted to clean the TDC sensor and retry cranking, but its hot, the owner is not my friend, and my care factor ran low.
I'm still curious about my logic though, should the tacho needle move during cranking???