Can anyone help me find the part needed to keep my tach from reading 4000 RPM constantly? I think it is the small filter on the firewall, but have not been able to locate one.

Thanks
John:D

You have NOT supplied enough info; I can only assume you must a CD Ignition and the Tach isn't working. There are special filters for that problem.

I have 80 Z-28 350 (only 29k mi on this car) all original equipment HEI ignition.
sorry for lack of info.

It sounds like the tach is bad. Does it drop to ZERO with key on and engine off?

No it does not. {but it never did} I am waiting on a tach filter I ordered last Friday thanks to a lead from this site. Hopefully that cures it.
Tks
:yes: