Evening everyone. Gotta a quick question about my tach and speedometer. The tach appears to be working fine at idle. However, at higher speeds, I believe it is not correct. For instance, in overdrive at 65, it is running 4k.

Second, the speedo tends to "bounce". While driving at 65, it will bounce back and forth between 63 and 70.

Any help on fixing these issues would be greatly appreciated.

Thanks in advance
Bob

 

Part A: Likely the typical tach calibration problem of fading capacitors/resistors on the backplane. Good luck with that one. If you had a signal generator you could experiment with components until it was again calibrated properly.

Part B: Likely a stick speedo cable. Pull it from the housing, clean it, and relube it with graphite powder. IIRC, the Camaros still had a cable drive speedo in '89, with the VSS on the back of the IP.