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Tach. signal problem

Discussion in 'Chevy Trucks' started by Silverado84, Jun 4, 2000.

  1. Silverado84

    Silverado84 Junior Member
    Messages: 7

    Anyone ever seen thisone before? I recently installed a tachometer in my 84 half ton Silverado-305, HEI dist. I'ts hooked up correctly, but the needle &quot;jumps&quot; anywhere from 200 to 500 R.P.M.'s....at IDLE or STEADY throttle ONLY !!!!!!! Under acceleration the needle is steady & appears to work correctly !!!! A bad module ?? a wobbly shaft ? an elect. prob, somewhere else????? Thanks, in advance, for any advice given.........Jesse<p>----------<br>Jesse Sketo<br>Jesse Sketo
  2. bob149

    bob149 Guest
    Messages: 0

    lots of low end tachs wont work well with HEI. Some come with a little potentiometer that needs to be wired into the signal (green) lead. this can be adusted to take out the bounce.