1967 Camaro Factory Tach Not Working Properly

[JJs 67 Camaro]

Hello everyone- I am having trouble with my tach. It works, but it is giving a high reading and when I give it gas it really jumps high. I put an analog tach to it at the same time. The analog reads 800 and the factory tach reads 1500. I recently had it services at Redline- good guy. It seemed to work initially but went erratic again. I have done the following:

Confirmed i have power to cluster- all lights work, blinkers, etc.
Changed the coil
Took each screw out of the housing cleaned and put back

When the tach broke the first time, he indicated the ground wire in the back of the tach came loose. He fixed it and it seems still connected. Am i missing something. Is there another ground i am not aware of?

Thank you. I appreciate the help.

Jerry
     

[69pace]

Factory dizzy with points or converted to HEI?

[JJs 67 Camaro]

factory distributor with Pertronix igniter inside.

[69pace]

LOL Sorry for the delay. Hope you have figured it out but most HEI systems make the analogue tachometers crazy. You in most cases have to use a tach filter. If you are still having the problem cruise over to Team Camaro and look at the diy tach filter sticky in the electrical section.

[Stingr69]

I sent mine to "Gary The Tach Man".  He will make it work.  Not cheap but it works great now.

[L78 steve]

Pertronix should not need a filter. I have the Accel module in my 67 and the tach works fine.