I have run the black wire from the 1992 M50 ECU to the 1989 E30 under the hood plug Pin 9 black wire. I get power to the tach in that it jumps to a false reading of about 2500 rpm, but is unresponsive to any throttle inputs. Any help greatly appreciated.
I think you might need a coding plug? What E30 are you putting it into, a 4-cyl or a 6-cyl? Is the tach needle moving at all?
E30 tach The E30 was a 2.5 as is the M50 engine that is now installed; the needle jumps a little if I goose it a bit.
E30 M50 swap tach solved Tried a different tach in the same cluster and it works. Anyone have any ideas if the 1st tach is likely junk or some kind of sending/control/whatever type deal?
