well i just finished my b18a1 swap on my si hatch and all the gauges work and all the lights work (batt light,CEL,oil,exc)and the speedo and temp and gas gauges all work expect the tach/rpm gauge. does anyone have a wiring diargam or some useful info on how to get this thing going? im sick of hitting the rev limiter lol.

 

The rpm signal comes from a blue wire that runs from the igniter unit to the cluster. Have you checked the wire?

A bad igniter unit or tach could also be the problem.