Tach stuck at 4k when car is idling

[erniet17]

Anyone know how I can get the stock tach on a 1991 to function properly? The car idles like at 900 but the gauge is at 4,000. Any ideas??? Thanks

 

[skinnypGT]

if you pull the gauge cluster there is a chip on the back of the tach. replacing that will fix your problems a lot of the time.

 

[erniet17]

Thanks. Where would I get that chip? At the dealer?

 

[skinnypGT]

when I replaced mine I had an old gauge cluster from another mustang that I pulled parts from.

I would look on these forums, e-bay or somewhere like late model restoration supply. since you are going to have to pull out the gauge cluster you may want to just replace the entire tach