HEI ign. module

[doylerl]

HEI ign. module information:

http://www.carbdford.com/tech/HEI/hei.htm

Previous problem:

http://www.fordfestiva.com/forums/showthread.php?t=28978&page=3

Wired this in and now it idles VERY rough. The idle adjustment is all the way, and it still only idles at 800-1000. This would be acceptable, but it shakes really bad especially 1200-2000 rpm range. The gas is 2 months old, so I don't think it could be bad already, and I let it warm up to temp. after sitting for 2 months. Anything else I should check on? New cap, rotor, plugs, wires, coil, etc.... Thanks

[Evil D]

Maybe it has to do with that being a V8 module? I've used that same setup on my 347 with good results but i never considered it for a 4 cylinder.

[FB71]

reverse the leads/wires from the pickup coil to the module. Reverse polarity on the HEI's input will cause exactly this.

[doylerl]

reverse the leads/wires from the pickup coil to the module. Reverse polarity on the HEI's input will cause exactly this.

That was my first thought, but when I reversed them, it wouldn't start at all, just make some popping noises.

[FB71]

ok, then the polarity is correct. Are you using shielded wire? Is the shield tied to a good ground?

[doylerl]

ok, then the polarity is correct. Are you using shielded wire? Is the shield tied to a good ground?

Not exactly sure what you mean when you say "shielded"... The module has a good ground, if that is what you mean...?

[FB71]

no, not the module ground...

The wires connecting the coil to the module need to be a twisted pair, 1:3. One twist for every three inches, minimum. That twisted pair needs to have an aluminized Mylar shield with an uninsulated conductor wrapped around it. One end of that uninsulated conductor needs to be grounded, but ONLY one end, so it doesn't set up a ground loop. You should be able to get shielded wire from Radio Shack.

[FB71]

dumb question... are you using resistor core plug wires, or solid core?