Tachometer needle bouncing around over 4000

Discussion in 'Troubleshooting & Diagnosis' started by JD Z, May 4, 2021.

  1. JD Z

    JD Z Veteran Member

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    I’m looking to track down the likely contributor to my tachometer issue. It works as normal until it gets to 4000 RPM and the needle bounces around like crazy. The car runs great, just the needle bouncing. It’s a 1980 Z28.

    Would things like the tach filter contribute? I’m hoping the tach doesn’t need to be replaced.
     
  2. Fieryfrog

    Fieryfrog New Member

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    Following. I am also running a 1980 Z28, but my tach is bouncing at all times.
     
  3. JD Z

    JD Z Veteran Member

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    From what I’ve picked up, I’m going to remove the tachometer filter first (it’s right behind the engine bolted to the firewall). Someone said that fixed this problem. Then, I’m going to replace the filter if that does not work. From there it’s onto replacing the tach board. I’ll update when I have one.
     
  4. Ihada70Z28B4

    Ihada70Z28B4 Veteran Member

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    MChamp likes this.
  5. JD Z

    JD Z Veteran Member

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    SOLUTION: Bouncing tach needle. I replaced the tach filter and that didn’t help. The connection at the distributor was loose. I disconnected it, cleaned it up and tightened it up so it fit snug. The tach runs like new and smooth all the way up the RPMs now.

    Hope that helps someone. Best!
     
  6. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    Excellent information!:cool:

    I knew the difference between a 6 & 8 cylinder tach was a single, simple component but I never knew which piece.

    Is this your site?
     
  7. COPO

    COPO Veteran Member Lifetime Gold Member

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    Always start with the connection at the dizzy before forking $ for parts that may not be needed.
     

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