Its a new setup and Im just starting to tune it. So I took it up to past 5000 rpms and then the tach needle goes haywire. Spins the other way and all sorts of crazy movements. When RPM drops below 5000, then it functions normal. Anyone ever experience this? Car is OBD2 Integra Turbo with OBD1 Neptune Demon P28 and conversion harness.

Also running OBD 1 dizzy with conversion harness.

 

This occurs with some obd2b to obd1 harnesses.
Read: https://honda-tech.com/forums/showth...hlight=a21+a25

 

Thanks so much

 

By chance are you running an aftermarket distributor or do you have a 100% OEM dizzy on this?

 

Its 100% OEM, but engine is OBD2 vtec and Dizzy is OBD1 LS. Im going to look over my ecu conversion harness and trace those wires in the link.

 

I've seen this many times. After switching to OEM Honda ignition module the problem ceases