I had my tach rebuilt last year at the tach shop . When I start up my car the tach jumps up to 5000-6000 rpm. After car is running it will setle down and show the proper rpms. can any one help me wth this problem.
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can any one help me wth this problem.

I have no ideas other than since you paid someone for their 'expertise', perhaps you should dump this back in their laps?

Did you do any other changes at the time or just rebuild the tach? New distributor, coil, etc?

I completly rebuilt the car. I installed a promaster mallord coil .The company who rebuilt tach wants me to ship it back to them but I don't think it has any thing to do with tach.
I realy don't want to pull out the tach. Once car is runnig tach works .
Don't hold your foot on the gas when you start it! Wink Just kidding' I have seen gauges that cycle up and down with the switch being turned on. I figured it was a test of sorts. Maybe they added that function?
Removed my tach to day what a pain in the back will be sending back to the tach shop for repair . I will give up date when it comes back thanks for your replys. dead horse
The Tachshack checked out the tach and said there is no problem with the tach. I clean the ground wire for tach . Can any one help me. I thing it must be a problem with the wire going to coil.


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just happened to be looking at the wiring diagrams, stock the cars had a 1.4 ohm resistor wire or I here that some had a Ballast resistor.
There is also a wire coming directly from the starter relay for a hot spark during startup and this may be were spike is coming from.
but I must say I have never noticed my tach jumping as you describe, just never paid it any mind, will be looking now though.

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