I have a 1980 CJ5 Jeep, with V8 engine. I have very extreme ignition
noise, of course on am only. Fm works fine.
I have replaced the plugs, and later installed high quality, carbon core
plug wires.
Someone here ( I think Mike Romain, not sure) has said that a defective or
worn braided strap from the engine to the firewall may cause severe ignition
noise, and other problems. I am not a mechanic, but I have looked for
this wire, and don't find it. Is it visible from under the hood ?
What other efforts can I try to get rid of this ignition noise ?
Thanks !
James
DougW - 23 Mar 2008 19:04 GMT
> I have a 1980 CJ5 Jeep, with V8 engine. I have very extreme
> ignition noise, of course on am only. Fm works fine.
[quoted text clipped - 9 lines]
>
> What other efforts can I try to get rid of this ignition noise ?
Easy first shot to check the ground strap is to use your jumpers
and ground the engine block to the battery or frame.
Do you have points in the distributor? If so there is a little
capacitor in there that has to be replaced.
The strap comes off the back of the engine or on the later I6
from the same mount as the ignition coil on the right side.

Signature
DougW
Mike Romain - 23 Mar 2008 19:16 GMT
> I have a 1980 CJ5 Jeep, with V8 engine. I have very extreme ignition
> noise, of course on am only. Fm works fine.
[quoted text clipped - 12 lines]
>
> James
Your engine should have one mesh strap going across an engine mount to
ground the chassis frame and another going to the firewall from the back
of the engine. It is top dead center so if you don't see it is isn't there.
Some folks wire them with a cable from the battery negative to the
firewall or fender. The fender isn't really a good ground, too many
bolts to rust up between it and the tub.
The mesh cable is also the best one for RF noise. A battery cable
ground will transmit noise better.
The stereo also might want it's own ground to the battery so it doesn't
use the noisy body.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com
Scott in Baltimore - 24 Mar 2008 00:07 GMT
> The stereo also might want it's own ground to the battery so it doesn't
> use the noisy body.
My old car started to lose it's grounds and cause noise in my stereo system.
I solved it by taking a wire from the radio to the equalizer to the crossover
and the front amp and from there to the chassis behind the dash out to the door
frame and ending up at the battery's negative terminal. My stereo never got noisy
over bumps again.
Use stranded wire in mobile applications. Solid wire will break sooner from flexing.