Tachometer Issues
Thread Starter
1st Gear
Joined: Aug 2022
Posts: 1
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Tachometer Issues
Hi long time reader, first time poster. My 78 seems to have issues with the tachometer reading either 0 (at idle) or 3500 (when giving her gas), sometimes it reads fine then all of a sudden the issue begins again. Not sure if its a problem with the filter or tach board. Searched the forums and didn't find much help. Any advice would be appreciated.
Race Director
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Sounds like classic symptoms of a bad board.
6th Gear
Joined: Oct 2021
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I had similar tach problems last year. Replaced the tach circuit board. Didn't fix it. Replaced the tach filter and it cleared things up...for a little while. After de-winterizing this year, the tach has started acting a little "wonky" again. By "wonky" I mean it works about half the time. Sometimes I start it up and it pegs...sometimes it works just fine. "tis a head-scratcher...
Le Mans Master
Joined: Jun 2019
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From: Indiana
I had similar tach problems last year. Replaced the tach circuit board. Didn't fix it. Replaced the tach filter and it cleared things up...for a little while. After de-winterizing this year, the tach has started acting a little "wonky" again. By "wonky" I mean it works about half the time. Sometimes I start it up and it pegs...sometimes it works just fine. "tis a head-scratcher...
Race Director
Joined: Nov 2006
Posts: 13,236
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
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Cruise-In VIII Veteran
Back around 2005, give or take. My tach was acting just like the OP's . very same symptoms. New tach board from one of the vendors. Pain pulling the drivers side dash out. But tach has been fine ever since. I did try a new tach filter first. No difference.
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Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
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Cruise-In VIII Veteran
Maybe you just got a bad one??
Le Mans Master
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From: Indiana