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Old Feb 1, 2007 | 08:41 AM
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Default Tachometer problem

My Tach is bouncing. Like when I'm cruising around lets say 3k, it will bounce up to 3.5k-4k. Any ideas?
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Old Feb 1, 2007 | 10:07 AM
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It's your VSS.
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Old Feb 1, 2007 | 10:49 AM
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What is a VSS? Is it easily fixable or replaced?
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Old Feb 1, 2007 | 11:03 AM
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Vehicle speed sensor...it's easily replaced. It's a little sensor on top of the rear part of the transmission.
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Old Feb 1, 2007 | 11:22 AM
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negative.
VSS is only what it says. Vehicle speed. if you don't beleive me unplug and drive around the block. speedo will stay on 0, tach will still bounce. pretty sure the tach just reads the pulses from the distributor.
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Old Feb 1, 2007 | 12:03 PM
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I could be way off but i have heard that a ignition coil going bad can cause tachometer bouncing. someone correct me if i'm wrong...

Does it idle up and down when your at a stop? or just when cruising?
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Old Feb 1, 2007 | 03:52 PM
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Just while cruising. I talked to a mechanic on the phone and he said it definatly wouln't be the vehicle speed sensor. The one I talked to send to see if anything was loose in the distributer? I called a couple of places and two said that it could be a bad instrument cluster, and some said it was an electrical issue? They said to take it to dealer to check out. I am somewhat confused, so i will probably just do that instead of paying 80.00 for a diagnostic (that probably won't do anything since I don't have a CEL) and then be told to take it to a dealer.
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Old Feb 1, 2007 | 04:00 PM
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Buy a multimeter (if you don't already have one), download the Helms manual available in the FAQ, and troubleshoot it yourself. The problem could only be in the cluster, wiring to the distributor, or the distributor itself. I strongly believe something in the distributor is acting up. You better troubleshoot it soon before something fails, leaving you stranded.
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Old Feb 1, 2007 | 06:18 PM
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my vote would something in the distributor or just a loose connection somewhere. find out which wire you need look at and go through and check all the connections, maybe sand some of the contacts. things like this are really hard to diagnose because you will have a circuit but something is causing an interuption or noise.
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Old Feb 1, 2007 | 07:57 PM
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Originally Posted by bnuk
negative.
VSS is only what it says. Vehicle speed. if you don't beleive me unplug and drive around the block. speedo will stay on 0, tach will still bounce. pretty sure the tach just reads the pulses from the distributor.
That's funny, because I had the same problem, replaced the VSS, and it was fine.
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