crxrocks

I am working on installing a PLX-R300 to do some datalogging in my CRX. The PLX can log RPM but it requires a speed input to do so. I was looking at the pinouts for a ODB0 ECU and noticed that there are two pins for the Ignitor Unit, B15 & B16 (based on a wiring diagram in the Helms these look like they are connected to the same wire further up in the wiring harness).

The question -> Do those provide a pulse input to the ECU (similar to the VSS input)? I am not in a position to have my car running right now, so I can't just figure it out w/ a voltmeter.

Thanks!

Chris

NJcoupe

You need the RPM signal, not the ignitor signal, So what you actually need, is the Coil - for the tach signal.

crxrocks

Thanks! Instead of running a line from the distributor I would like to just grab it from the ECU harness if possible. Does the ECU determine engine RPM based off of some calculation or does the ECU get a signal from the distributor?

Again, thanks for the help!

Chris