Pull tach/rpm signal on M50 (individual coils)?

[Jon K]

On the m20/30 they just tap the coil or distributor.... i need to send my standalone ECU a rpm signal... what should I tap?

[Anton CH.]

Do you need to know just the RPM or when each cylinder actually fires? If RPM then just use the wire that goes to the crank postion sensor on the front harmonic damper.

[Strap]

Hey john ,

You should use the tack lead from the diagnostic plug, it is the only solid black wire in the 20 pin plug ( only about 10 wires are in there) it is the true tach signal rpms going to the ecm. not cycled through the ecm yet and before the instument cluster. This is the signal i use for installing remote starters in bmws.
Good luck
Strap

[Jon K]

Hey john ,

You should use the tack lead from the diagnostic plug, it is the only solid black wire in the 20 pin plug ( only about 10 wires are in there) it is the true tach signal rpms going to the ecm. not cycled through the ecm yet and before the instument cluster. This is the signal i use for installing remote starters in bmws.
Good luck
Strap

I'd like to tap somewhere near the stock ECU. Where does that black wire meet up in the engine bay? I don't want to pull the cluster out, I am trying to install a standalone fuel control ECU.