Hey guys I have a 98 civic ex coupe 5 spd. The tach. will go to 4000rpm with the ignition on motor off. When I start it it goes to 0 RPM and stays there. What should I check other than the gauge itself because I already replaced that. Thanks!!

 

If you disconnect the blue wire from the ICM, does the tach needle now stay at 0 rpm under all conditions?