Hi folks,

Newbie to the site. I tried a search on jumpy/bouncy tach and didn't find anything of much use.

I have an aftermarket tach and the signal to it appears to have noise above about 2500 rpm but only under acceleration.

I replaced the cap, rotor and wires and re-ran the tach lead with shielded wire (shield is grounded)

This is on a 1989 2wd pickup 1/2 ton with a 22R.

I'd usually live with it but there's an aftermarket audiovox cruise control on the truck that cuts out anytime there's a slight requirement to accelerate a bit when the cruise is on.

Could it be the ignition module?

-a

 

Even better when one solves their own problem.

bad spark plugs caused this, I might add very bad spark plugs too.


-a

QUOTE=abeaudin1971;50613988]Hi folks,

Newbie to the site. I tried a search on jumpy/bouncy tach and didn't find anything of much use.

I have an aftermarket tach and the signal to it appears to have noise above about 2500 rpm but only under acceleration.

I replaced the cap, rotor and wires and re-ran the tach lead with shielded wire (shield is grounded)

This is on a 1989 2wd pickup 1/2 ton with a 22R.

I'd usually live with it but there's an aftermarket audiovox cruise control on the truck that cuts out anytime there's a slight requirement to accelerate a bit when the cruise is on.

Could it be the ignition module?

-a[/QUOTE]