Electronic noise...

FrankNB

Ever since my TFI upgrade I notice a great deal of noise in my CB(i.e. engine rpm).. How do you troubleshoot this kind of electric interference or whatever the real name of it is? Is there something to cure this?

pyagid

I am not sure how to diagnose it. But a lot of times it has to do with a ground, needing an additional one. Or possibly try a noise suppresor.

There is some info here

http://www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/noise.html

hope it helps

-Paul

FrankNB

it is probably ground related... I had my starter wire short on my exaust manifold.... I'm gonna clean my grounds up and see what happens...

ROBERT11

It is called EMI, electromagnetic interference, and yes the most likely cause will be a ground; anything you rewired with your tfi could be suspect, clean and check your connections, the suppressor should be a last resort.

ROBERT11

also rust and unlike metals can cause it too.

LEVE

FrankNB wrote
Ever since my TFI upgrade I notice a great deal of noise in my CB(i.e. engine rpm).. How do you troubleshoot this kind of electric interference or whatever the real name of it is? Is there something to cure this?

I assume it's RPM related. If that's true I'd start looking at the plug wires, plugs, coil and distributor. Each of these can cause RFI to be eminated...Of course you've boosted the voltage to the plugs using the TFI upgrade. Now you need to contain it... in the wiring and plugs. If you did not change your plug wires then that's where I'd start. A good upgrade to Resistive wiring and resistor plugs may help and the cost is not too bad.

FrankNB

Ok, I'll leave the punch for the end.. but first, I changed my wires for MSD 8mm wires and the plugs are copper plugs.. Grounds are not too bad.. now here's the punchline... I just noticed that I grounded the CB and the tach together.. That might have something to do with it :razz: I also think my antenna isn't the best thing in the world.. I like those Firestik, but they're so stiff they keep breaking my stud mounts, and I loose an antenna a year... it gets expensive... so I put a flexible trucker antenna..

Goose

Old CB trick.. take your extra antena lead and instead of coiling it or stuffing it gently coil it in the shape of a figure 8 (about a foot long or so, just not too small) then with the last foot or so wrap it around the middle of the 8 like you were storing an extension cord.. wire tie it in the middle to keep it together, this forms a RF choke out of your lead and it will cut down on stray RF interference ( If the ground issue with the tach doesnt clear it up..)

FrankNB

cool, I got the figure 8, but not the extra coiling.. I will try... thanks..