My Tach sometimes twitches, it will move when I'm not looking, but stay still when I look at it
How can I tell if it's the tach or the tach filter?

Oh ya..It's an 82

 

1. check for broken, or near broken, wire between the distributor and the tach.

2. I don't know where the filter is located on an '82 but on mine it's mounted at the rear of the intake manifold. Your's might be behind the dash.... follow wiring and bypass the filter.

3. Take dash apart and pull tach, common problem is the circuit board is shot......

 

The tach filter on my 75 is mounted on the intake manifold right behind the carb. My tach has been acting squirrely at 3000 rpm. George (George@a-c-e-computer.com) was kind enough to send me a breadboard filter that he had made up. I have it now. I promised it to Captain Morgan (c3sharklover@yahoo.com) as soon as I get off my dead a** and install it in place of my filter to see if that is the problem.

Captain, sorry I have been so slow in testing the filter. I will get if off to you asap. Please eMail your mailing address.