My 82 has a weird little problem with the tach that is annoying me...when idiling when its cold it is on the peg at 0 rpms and when warmed up it is about 250 rpms...when i am reving it or driving down the street it picks up just like normal...it seems to me that the tach is showing much less rpms than what my car is actually running...i am worried that if i was to shift my car at 5000 rpms that it would actually be higher than that...i dont know what it could be thats causing this so i was hoping to get some opinions and i would really appreciate it. Thank you

 

Can anybody help out? I dont know much so i would like some opinions from some other people

 

The Tach in my '82 Berlinetta acts weird too. It's seems fine till you rev it - then needle sometimes pegs to the other side! I've thought about taking it out & to a shop to see if it can be re-calibrated somehow!

 

Wow thats crazy

 

It's common for 3rd Gen. Tachs to be unaccurate. My tachometer is off by a lot... It reads 1500 when its really at 750... But it may cause late shifts, for the time being I would not over rev the car. I Don't believe there is any type of calibration for the tachs (If there is can someone help?), and the only real solution is to get an aftermarket tach.