RustRocket

I have an 82 Cutlass V6, and I noticed my Tach was sitting around 2k when the motor wasn't running. I closed the driver's door and it jumped to 3.5k, then I just knocked on it with a knuckle and it jumped to 5k. This is really strange, also at idle it reads 1,100, but I know it's not more than 600. At about 2,500 the Tach reads 6,000. Is this an easy fix? Should I just replace it? Is calibration easy to do? Any input is great, thanks

CutlassDad

I'd say the symptoms are terminal. May the tach RIP.