My tach reads twice as high as the engine is spinning
04-21-2004, 11:08 PM
#1
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My tach reads twice as high as the engine is spinning
My tach reads almost twice what the Dwell meter does.
How do I remedy this? Also, what is the purpose of the tach filter and should a '80 have one?
How do I remedy this? Also, what is the purpose of the tach filter and should a '80 have one?
04-21-2004, 11:21 PM
#2
Safety Car
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Re: My tach reads twice as high as the engine is spinning (Ak. Mal)
Is the dwell meter tach set for an 8 cylinder engine? At a warm idle, what are the readings from the tach and from the dwell meter?
04-22-2004, 10:03 AM
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Re: My tach reads twice as high as the engine is spinning (Vetterodder)
Yes the Dwell meter is set for 8 cylinders.
With the engine warm and idling, dwell meter reads 700rpm, tach reads 1400.
If I rev the engine up to say 1500rpm on the dwell meter, the tach reads close to 3k.
With the engine warm and idling, dwell meter reads 700rpm, tach reads 1400.
If I rev the engine up to say 1500rpm on the dwell meter, the tach reads close to 3k.
04-22-2004, 10:39 AM
#4
Melting Slicks
Re: My tach reads twice as high as the engine is spinning (Ak. Mal)
I had the same problem in my '82 and fixed it by replacing the circuit board on the back of the tach. It was pretty cheap and easy to fix.
Here's Ecklers site for it. It was cheaper when I bought it.
http://www.ecklers.com/product.asp?p...8PWCGTRRNH72A5
Here's Ecklers site for it. It was cheaper when I bought it.
http://www.ecklers.com/product.asp?p...8PWCGTRRNH72A5
04-22-2004, 10:50 AM
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Re: My tach reads twice as high as the engine is spinning (SuprJames)
How do you go about replacing the circuit board. I've got the guage cluster out, but haven't bothered to look at the tach very closely.
04-22-2004, 10:54 AM
#6
Melting Slicks
Re: My tach reads twice as high as the engine is spinning (Ak. Mal)
Oh man...it's been awhile. I think there were a couple small nuts to take off or something. If you already have it out, the circuit board, if I remember right, should be right on the back of the tach sticking out. It's real easy to do.
