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Factory Tach problem

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Old Apr 7, 2010 | 12:42 PM
  #21  
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From: Glen Allen, VA
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According to Willcox's instructions, the tach wire to the distributor should be disconnected when you turn the key on, and the tach should read 0 at that time. However, I have moved the needle to 0 with the tach wire disconnected and also with the wire connected and the key to the on position, both with the same result.
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Old Apr 7, 2010 | 05:49 PM
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OK.....with the tach completely connected, key on 'on' and motor not running, and the needle manually removed and put back on at 'zero', when does it go to 3000?
When you start it and it should be at like 700 with the idle?

And it's the same with either board?

Last edited by KapsSA; Apr 7, 2010 at 05:51 PM.
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Old Apr 7, 2010 | 10:10 PM
  #23  
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Mike, It goes to 3000 as soon as you turn the key on, without starting the car. If I set the needle at 0 with the key on, then turn the key off, then turn it back on, it will go to 3000 every time. No matter whehter it's my old board or your new board.
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Old Apr 7, 2010 | 10:28 PM
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What would happen if when you turn the key back on and it goes to 3000, if you pull the needle off again and put it back to zero?
Does it go to 3000 yet again?
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Old Apr 9, 2010 | 08:38 PM
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Default I have not quite the same problem, but...

I am so glad I found this forum!

I have read so many articles about tach problems but mine is different, at least I think?

I have a '79 L-82 that I've owned for 8 years. The car has 27,000 mile on it now.

Every article I read is about a tach that doesn't work at all.

My problem is that the tach does work but will never go above 1000 rpm. When I start the car and or in nuetral, the tach reads about 500 rpm's. I did replace the board but it didn't help.

I was wondering about the tach filter or even I read one article about moving the needle manually to free it as it might be stuck???

I am hoping someone here might be able to point me in the right direction.

Thanks for any advise with this problem.

Paul
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Old Apr 10, 2010 | 08:04 AM
  #26  
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Mike, yeah, that's exactly what it does, if you turn the key on, it goes to 3000, then you remove the needle, set it at 0, and turn the key off. When you turn the key back on it goes to 3000. Every time, whether the new or old board is installed.
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Old Apr 10, 2010 | 12:09 PM
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I THINK they have like an old wristwatch circular spring that's bathed in oil.
Spring broke? Sounds like a balance thing, where it just goes to a certain place due to the weight of the needle.

This is speculation on my part as I've never been that deep into the tach.

Anyone you could swap tachs with for a test? As you know it's only like a 15 minute job.
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