Goofy Tach
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Goofy Tach
My 1979 has a tachometer that is ill. Idles at 1500 but new motor is certainly not. At 50mph tach at 4500. When I stomp on it, tach goes off the end. When I turn on the key before starting, goes to zero like I think it should. What do you all think, new tach board. Filter is in place
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Joined: May 2001
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From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
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St. Jude Donor '06-'10, '13
Try bypassing the filter and see what you get. Also try a hand held or another small tach wired direct to the distributor. This will help you find out if it's the dist., filter, or tach board.
Mine would run fine up to 2500 RPM and then start going backwards. It was the tach filter.
Mine would run fine up to 2500 RPM and then start going backwards. It was the tach filter.
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Joined: Oct 2006
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From: Jupiter FL
Try bypassing the filter and see what you get. Also try a hand held or another small tach wired direct to the distributor. This will help you find out if it's the dist., filter, or tach board.
Mine would run fine up to 2500 RPM and then start going backwards. It was the tach filter.
Mine would run fine up to 2500 RPM and then start going backwards. It was the tach filter.
If it goes to zero when you turn the key on and then starts acting erratically as you drive or idle, I'd by-pass the filter as well. If it continues to do it, one problem, especially in warmer climates is the needle has a damping effect. There is an oil inside the meter head that may dry up. The needle may swing freely and not settle down, and fluctuate a lot. It needs to be re-damped. (But my first guess is the filter may be shot)
Le Mans Master
Joined: Oct 2005
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From: Glen Allen, VA
On my 79 the tach also reads way high. It shows about 5000 at 70 mph. I have verified that 1200 is really 800 and 2000 is really 1200. I have no filter on mine and it never has in the 1.5 years I've had it. It's on my list of things to get sorted out, so I'll be watching this thread to see what comes of it.
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Goofy Tach Fix Failed
Tach runs real high, tried to disconnect the tach filter and tach quits altogether. I have an upraded stock distributer, not the 1979 original with a GM create motor. Some still say tach board. Why does tach quit when filter diconnect?
