Tach slowly rising
Tach slowly rising
Hi I have an 86 Camaro Z28 with an Edelbrock Carb and a HEI distributor
There is a white wire on the TACH output from the HEI
My TACH meter when I put on ignition is slowly rising, and not getting any impulses. It just keeps rising slowly to beyond max
Do I need a new circuit board, or could it be something else.
Someone told me to have a new wire from the tach, to the HEI, but that seems quite hard, because there is a big plug with wires going on the back of the tach console, so theres not like any fixed connector to attach the wire.
There is a white wire on the TACH output from the HEI
My TACH meter when I put on ignition is slowly rising, and not getting any impulses. It just keeps rising slowly to beyond max
Do I need a new circuit board, or could it be something else.
Someone told me to have a new wire from the tach, to the HEI, but that seems quite hard, because there is a big plug with wires going on the back of the tach console, so theres not like any fixed connector to attach the wire.
Joined: Sep 2005
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Tach slowly rising
Most likely the tach itself is bad. Specifically, the little square circuit board mounted on the back of the actual gauge.
I'd recommend leaving the wiring COMPLETELY alone, to prevent the inevitable problems that inevitably result from butchering it.
I'd recommend leaving the wiring COMPLETELY alone, to prevent the inevitable problems that inevitably result from butchering it.
Supreme Member

Joined: Jan 2008
Posts: 1,328
Likes: 560
Car: 1986 IROC Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.23 Posi
Re: Tach slowly rising
No.....just.........................no.
Instead, vvvvThis.
Instead, vvvvThis.
Re: Tach slowly rising
I have a colleague who knows a lot about electronics he said it might be the electro capacitor on the circuit. Because the gel inside dry out. A new one costs about 50.cents. so I will try and change it on the board.
Will post what happens..
Will post what happens..
Joined: Oct 2020
Posts: 1,354
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From: Franklin, KY near Beech Bend Raceway, Corvette Plant and Museum.
Car: 1992 Pontiac Firebird
Engine: 5.0L L03 TBI
Transmission: 700R4
Axle/Gears: 2.73
Re: Tach slowly rising
Tach problems are common on 3rd gen Camaros. This replacement tachometer circuit board is regarded as an excellent part and has two LEDs that verify the circuit board is getting power and RPM signal.
1982-89 Camaro V8 Tachometer Circuit Board, LEDs | Cajun Tach Shop
Without being there in person to diagnose the problem I can't guarantee your Camaro has a bad tachometer circuit board.
If you go to their homepage and scroll to the bottom they have a Contact Us section where you can send them a message or call them on the phone.
1982-89 Camaro V8 Tachometer Circuit Board, LEDs | Cajun Tach Shop
Without being there in person to diagnose the problem I can't guarantee your Camaro has a bad tachometer circuit board.
If you go to their homepage and scroll to the bottom they have a Contact Us section where you can send them a message or call them on the phone.
Supreme Member

Joined: Jan 2008
Posts: 1,328
Likes: 560
Car: 1986 IROC Z
Engine: 5.0 TPI
Transmission: 700R4
Axle/Gears: 3.23 Posi
Re: Tach slowly rising
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