Creating a points driven HEI unit

GrimGreaser

After looking at Pertronix and Crane points replacement kits the other day and seeing a points triggered transistorized ignition kit on a electronics hobby site I got to thinking about using the old HEI module I had laying around.

So, searching around the internet I stumble upon this site:

Points driven HEI

And it has instructions and schematics to wire up a 4-pin GM HEI module. Score! Only problem is the module I have is a 5-pin (had Electronic Spark Control), though I've read tying two pins together bypasses the ESC and it will then behave like a 4-pin module. So, I make my little circuit and hook everything up... Nothing. Nuts.

So after a couple days scratching my head (there's little to no info on the 5-pin HEI modules) I experiment and see that my 5-pin behaves different than the one described in the link above, instead of needing a ground-path at the input, I need to apply a voltage signal. Add a single resistor in the circuit between the input pin and +12V source and I'm good to go.

Haven't tested it on the car yet, I will this afternoon, but everything was working right last night. And if I can figure out the ESC control, I can pull 10-20 (I've read varying accounts) degrees of timing out on demand. I'll attach my circuit later when I get a chance to draw it up.

Oh, and I'm only in it for $15 right now.

Further links:

Points controlled Chrysler and Ford TFI modules

Transistorized Ignition Kit

GrimGreaser

It works!

I was getting a bit of a stumble right off of idle, it was real bad before adjusting the points and better, but still present, afterwards. Now, not a hiccup! Even with too much carburetor. We'll see how it works when I get out and drive it.

GrimGreaser

5-pin HEI module circuit attached:

mars55

For those who are running 6 volt positive ground point system, the Pazon ignition unit can be fitted for about $84. See link.

http://www.pazon.com/ignition-system/energy-booster-ii-positive-earth.html