Cross post!! Help, where to read RPM voltage?
 

I am trying to datalog my RPMs, but I need a voltage output.

Is the signal from the ECU to the tachometer a voltage signal?

Which wire should I tap into?

Or do I need to get another tach circuit board and read off of that?

Thanks


thesaint

p.s. for whoever is interested I am planning on datalogging my MAP voltage, wideband o2 sensor output, and rpms to tune the car.

Along that note, does the InterAcq software for the EFI PMC allow you to log other inputs? As far as i understand all possible inputs to the PMC are already used.

RPM signal is usually a pull-down voltage (i.e. negative).&nbsp So the wire will typically "float" then go to "0" when you get an RPM pulse.



-Ted