76REDSTINGER

i just replaced mt circuit board on my tach (76 vette)

i put power to it and reinstalled the needle to zero it

it seems to work fine......unless you hammer the throttle
then at about 4000 rpm the thing goes nuts
up and down from 0 to 6000rpm
untill you let off the throttle and then it is fine until you hit it again.

kona

Sounds like you need a new tach filter.

Kona

76REDSTINGER

yes

i cant find one under the hood, what did the original look like?

isnt there a guy on the forum that makes them?

kona

The original looks like a condensor and should be located right next to the distributor on the intake. There is a tan? wire coming from the distributor to it.
I just got one from Rodney Dickman you can find him on the web I think I paid $25 but it does not look like the original. He has a reproduction but I think it runs $50.00. It solved the problem that I had which sounds exactly like what you are experiencing.

Good luck, Kona

76REDSTINGER

i found the original

it was on the intake...but there is no wire left coming out of it

also how was it wired in with only the one wire.....it went to where?

R

76REDSTINGER

what is his forum name, want to find him

thanks
R.

SteveG75

Brown wire from harness to filter, brown wire from filter to tach terminal on HEI. I had to resolder my leads, they break off very easily.

Pete76Shark

Is this part also called a coil capacitor ? if so Zip has it

jeromeunderwood

I had a similar problem with my 82... I found the capistor was not grounded and the HEI wires were running through some sparkplug wires. Not sure which one fixed it but started the car back up and it has all be fine since.

Schmucker

Yeah, I had to resolder mine as well after I broke one of the leads off. Someone unbolted it from the manifold so it lost its ground so it didn't function. It works now after bolting it down.

Eckler's has an original looking one ($30) and a non original looking one ($60). Madvet has the original style one for cheaper though ($50).