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Discussion Starter #1
After about 2 years of faithful operation, my after-market tack has pinned itself all the way over to max revs. Yet the shift light still works properly. What's with that?
 

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Doc here, :pimp:

If you haven't accidental hit the Cylinder Select knob, and the Red and green wires weren't shorting together, I'd say the Tach unit has Lost Frequency to analog converter, Or the meter is getting a high current source it shouldn't.

Check the select knob (if you have one..) and the red and green wires for shorts..If good replace the tach..(unless you wish to attempt to rebuild the unit..)

Doc :pimp:
 

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Discussion Starter #5
Tack needle pinned

I checked out the tack setting. It was still on 4 cylinders. I moved it up and down to no avail. The wires are clean and still attached.

One thing may be significant. With the lights on, I would notice an occasional flash in the tack light, but it did not seem to have an effect on the needle. Could this have caused a melt down?
 

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Doc here, :pimp:

It might be..or it could have not been the light at all, but an internal part shorting out in the dark!

Doc :pimp:
 

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Discussion Starter #7
Tack needle pinned

It was a fairly inexpensive tach. I liked it because it had a remote shift light and an external knob for easy settings.

Thanks again for your help
 

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Doc here, :pimp:

You might try, If you feel inclined to do so, Pull the tach apart and carefully remove the calibration card, look for burned traces or burned components, If you find any, replace or repair as needed.

You have nothing to loose, it's already broke, and you are going to replace it anyway, maybe you can save it and keep the Tach you like..anyway, you can't break it more..

Doc :pimp:
 

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Discussion Starter #9
Tack needle pinned

Hey, Doc:

Good idea. I'll call it TACH 101.

Spent the day replacing my Carter electric fuel pump with an Edlebrock 1791. A lot of work since the fittings are in different locations. The Carter sounded like a machine gun. The Edlebrock is a lot quieter.

Animal
 

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Doc here, :pimp:

I hear ya on the noisy pump..

I have had good results with mounting the pump to a GM Transmission mount, then mounting the mount to the frame...Takes the hammer right out of it..

The rubber provides a sound deafening barrier that usually works good.

Doc :pimp:
 

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Discussion Starter #11
Tack needle pinned

I was surprised how much noisier the Edlebrock is mounted to the chassis than it was just holding it in my hand and testing it. I will try adding a rubber pad between the frame and the mounting bracket I made.
 
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