1985 911 Motronic Tach Signal

[chstephens]

I have installed a PLX Devices wideband O2 sensor in my 1985 911 track car. I need to tap the tach signal wire (vilet/black I think) and enter into the PLX device two data signal points. For example, 20Hz at 1000RPM and 150Hz at 5000RPM.

Questions: 1) Can anyone confirm the wire I should tap and 2) Does anyone have the tach signal frequency output for my Motronic box?

Thanks. Craig

3.5L NA - 300HP

[ChrisBennet]

I posted what you're looking for in this thread: Tachometer pulses per Rev??
-Chris

[chstephens]

Thank you Chris. This is exactly what I need.

Craig