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Old 05-01-2019, 08:28 PM   #1
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Rpms do not sit at zero with engine off?

Anyone have any ideas how to fix this?

I went to a friends shop and used one of his high tech scanners and saw literally every single function in the speedo but nothing to reset Rpms. Seems to read fine however its over reading by around 700rpms

Does it require a new rev counter?

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Old 05-02-2019, 06:47 PM   #2
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Any idea if the gauge faces were ever removed? Seems like the needle may need to be removed and reinstalled correctly. It’s a thought, but possibly not correct.
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Old 06-29-2019, 09:07 PM   #3
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Any idea if the gauge faces were ever removed? Seems like the needle may need to be removed and reinstalled correctly. It’s a thought, but possibly not correct.
I highly doubt they were, I read somewhere to reset it with some high end scanners so I borrowed a friends scanner and found literally a million options aside from anything to do with the rpm gauge
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Old 06-30-2019, 12:09 AM   #4
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Might need to go to a dealer for that. Not sure if the Durametric will do that function.
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Old 07-10-2019, 09:17 AM   #5
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Would it be possible to just remove the rev counter and reset the needle back to zero or possibly source a rev counter that sits on zero or would it not work like that
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Old 07-10-2019, 09:31 AM   #6
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Originally Posted by gti13 View Post
Anyone have any ideas how to fix this?

I went to a friends shop and used one of his high tech scanners and saw literally every single function in the speedo but nothing to reset Rpms. Seems to read fine however its over reading by around 700rpms

Does it require a new rev counter?
What is more important is where does the tach read with the engine running? If it is accurate running, who cares where it sits when the engine is off...…………….
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Old 07-10-2019, 11:32 AM   #7
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Would it be possible to just remove the rev counter and reset the needle back to zero or possibly source a rev counter that sits on zero or would it not work like that
Yes, the gauge motors in these clusters are not like some other stepper motors used on instrument clusters in that these are geared and have fixed stops, so there is no calibration with a diagnostic tool as in some other clusters.

If the gears somehow jumped due to impact or someone messing with it, you can CAREFULLY remove the needle and reset it at 0. Depending on the gauge, you may simply be able to turn the needle CAREFULLY against the stop (counterclockwise only on the tach) until it is zero'd. You will be all good then. I have done this quite a few times. To remove the needles you must twist and pull at the same time. Even doing this, you can sometimes pull the gauge motor apart, requiring you to remove the face, disassemble the gauge motor and reassemble it correctly. Easier said than done, especially when you have to figure out how to index the gears and spring properly. The first time you do it this can be a bit of a pain, but it is obvious once you get it. Be very careful with all of the components, as they are quite small and not difficult to damage.

FWIW, I do have new gauge motors for the late (2001+ 986/996 clusters) and sets of the LCD displays for the early clusters.

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