tach goes wild.
 

Driving my 85 se today and the tach started going nuts. Needle going up down, no rhythm just crazy. I've had them stick in cold weather, but not go nuts.

Any ideas?

the tach runs off of your trailing ignition. So ide check the ignitor. Also check grounds and make sure there good these old cars have ground issues after a while.

I Had the same issue and it was the battery strap(metal) touching a hot spot on the trailing coil.

Ill start there...

Moved some wires around and so far no issues! Thanks for the help.

OK issues back. I'll try the ignitor.

I had that and realized it was every time my cellphone was near it......

Issue has gotten a little worse. Now when I stop, the car sometimes shuts off?? The tach will bounce to the redline, the buzzer goes off and the car shuts off...

My mechanic hooked up another tach and it did not do anything on that tach. Weird..

Any help?