Ok, when my car is off my tach sits on the 7 grand mark. When I start my car the needle jumps to about the 2 grand mark and tries to hold but does not and falls back to the 7k mark. It does not work at all when driving. Does anyone think they know they problem? What could it be? ~Thanks in advance.

 

its broken.

 

Do you have MSD ignition? What year is the car and what motor/tranny do you have in it?

Need more info.

 

It is an 90 Camaro RS 305 TBI with the 700R-4 trans. No, I do not have MSD Ignition.