Here's something not too many people know about Civics. There's a BLU tachometer wire buried in a bundle of wires near the clutch master cylinder reservoir. It has a black rubber cap over it. Carefully pry the protective cap off and attach a tachometer or engine analyzer to set engine idle rpm. This wire comes directly from the ICM.

I'm thinking about trying to do the tachometer test. I'm really knew to fixing my car so I don't know where anything is or wuts it called. Where is the clutch master cylinder reservoir? Near my clutch I'm assuming.