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Thread: Twitchy Tach???

  1. #1
    Idling - Listen to it purr...
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    Twitchy Tach???

    My tachometer is twitchy around 3500 rpm's. ALL grounds have been cleaned. Has anyone had this issue? I am thinking of swapping in the tach guts from a spare gauge cluster that I have to see if it solves the issue. Car also has NEW plugs, new wires and a NEW coil pack.

    Stumped!

  2. #2
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    Maybe your alternator is starting to go bad?

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    Ninja Messiah kung fu jesus's Avatar
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    There is a wire that is from the ignition system (packs/cas/igniter,etc) that the tach uses to read the RPMs. This wire is usually the reason for that twitch.

  4. #4
    Idling - Listen to it purr...
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    Quote Originally Posted by Martin View Post
    Maybe your alternator is starting to go bad?
    Alternator is good! All bolts tight as well.

  5. #5
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    Is that wire replaceable? Part number? The only other thing that it could be is the tach itself going bad, just because it is 25 years old now...

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    Ninja Messiah kung fu jesus's Avatar
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    Look at the wire diagrams.

    You are using a shotgun approach of merely replacing associative parts. You need to diagnose the issue.

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  8. #7
    Idling - Listen to it purr...
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    Not really. I started out cleaning all of the grounds. Car had fairly old plugs and wires, so those needed to be replaced anyway as normal maintenance. Agreed on the coil pack, but I also travel a lot in this car and didn't want to take chances. Now I have an extra coil pack, lol.

    I will remove the gauge cluster and make sure the screws on the backside are snug. I have a few extra clusters so I could swap the tach out and see if that does it as well. The tach is 25 years old and could be worn out as well. Car runs great, so the twitchy tach is more bothersome to look at than anything else. It probably does it 75% of the time while cruising on the highway.

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