Tach problems
Melting Slicks
Joined: Mar 2000
Posts: 2,975
Likes: 1
From: Northwest Iowa
Re: Tach problems (bobt007)
Don't know if this will help you or not, but here goes.
When I had to replace my circuit board on my 75 ( keep in mind, 75 is when the vette went to electronic tach, though I don't know if was still electronic on the 81), there were instructions on "zero"ing in the tach needle after replacement of the board.
I think it went something like this.
With the key in the off position, your tach may read between 0 and 100 RPM. Turn the key to the on postion with out starting the car and the needle should go to "0". If it doesn't, you have to carefully pull the needle off the dial and replace it to point at zero. As I said, the key must be in the on position with the car not running.
Did this just start reading off, or has it always read on the low side? Your car may just have a curcuit board going bad.
When I had to replace my circuit board on my 75 ( keep in mind, 75 is when the vette went to electronic tach, though I don't know if was still electronic on the 81), there were instructions on "zero"ing in the tach needle after replacement of the board.
I think it went something like this.
With the key in the off position, your tach may read between 0 and 100 RPM. Turn the key to the on postion with out starting the car and the needle should go to "0". If it doesn't, you have to carefully pull the needle off the dial and replace it to point at zero. As I said, the key must be in the on position with the car not running.
Did this just start reading off, or has it always read on the low side? Your car may just have a curcuit board going bad.
