When the car is running normal the tach needle is pegged all the way to right.(engine is at normal rpm).When its idling the needle is around 7000 rpm. The motor has been rebuilt ,no problems with it. Can the tach be hooked up wrong to cause this. Also has new distributor.

Rick, does the tach "park" at the same place every time when you turn the key off?
Does it go to"0" when you turn the key on before starting the engine?
Chances are, the tach filter is damaged in some way, or was left hanging loose. If it was working fine before the dist swap, I'd double-check the wiring to the dist. The tach filter should be in the wiring coming from the "Tach" terminal on the dist cap, and should be a brown wire...assuming you are still using the HEI system. If the filter wasn't bolted back down to something on the engine to keep it grounded, it can cause the tach to be flaky like you describe.





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Joel Adams
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Yes it goes back to zero when key turned off....I will check the wiring when weather breaks(been raining)

|UPDATED|5/22/2016 12:38:58 PM (AZT)|/UPDATED|