Other than just eyeballing the tachometer inside the car, is there another way to accuratly measure the RPM's? I think mine should be at 750 at idle with all electrical devices turnned off. I've heard of the obd ii scanner, but that is probably expensive.

 

To cheaply do it? I'm unsure.

I know when I had a VAFC installed ($50 bucks or so) it would register the RPM and what not.