About 2 months ago my trailing Ignitor went out, and I wasnt working and almost broke. I tried to go cheap and buy them used but got screwed on two used ones on eBay. Then I came across a few posts where guys used GM HEI ignition modules to trigger DLIDFIS. So I figured why couldn't I used it just to trigger one coil until I could afford a new Ignitor. So I hollowed out my old ignitor and used it to make a connector, then wired up the HEI Module. I was impressed with how much stronger the spark is from the HEI module as opposed to the Mazda Ignitor.

I think I have the pick up wires going the right way because my timing is correct. If I reverse them, the timing is way off. The problem I am having is it is missing at idle and my tach flutters between 1,000 and 2,000 rpm. Over 2000RPM the needle is steady. If I disconnect the Module the Miss goes away but then my trailing coils don't fire, if I leave it connected it misses. The module is grounded to the body of the car with 2 self tapping screws, I got the power from the coil feed wire, the old ignitor is gutted and basically a jumper from the pick up coil to the 2 terminals on the HEI Module, and the other terminal is to the ground on the coil. The coil wire still goes to the distributor and then out to the 2 trailing spark plugs, same as stock. What did I do wrong?

 

Is this an FB or an SA? Dizzy are different and the SA one doesn't work as well as an FB one.

Otherwise I would think its maybe noise. How long are the leads bringing the dizzy signal to the HEI?

I have a link in my sig to my write up on how I did this. You may have seen it already.

 

I think your write up was the last one I looked at, the only way mine differs from yours is I used the mounting screws to ground it to the body as opposed to a ground lead. Im using a 4 pin module because I had it and I am still using the stock ignitor for the leading coil. The car is an 82. It is the distributor with the 2 J109 ignitors screwed to it. The leads from the distributor are actually from a MSD jumper that went from the box to the distributor I cute the plug off and put terminals on the end to hook up to the ignitor and HEI Module. I dont have a tape measure handy but it is between a foot and 18 inches long.

 

You could try shielding the cable. I bet it has a shield but when you cut the connectors and redid
them it may have been disabled. A shield can be made with foil or mesh and should surround the
cable from end to end and only be grounded on one end.

 

Ill give it a shot. Another thing I noticed tonight sounds like the spark is arcing in the distributor cap, I heard a ticking sound coming from there. Also it seems the tach flutters most on deceleration. Also when I turn the electric fan on or off it flutters a lot. Do you think its just not grounded well?

 

Run it at night and turn out all the lights. You may be able to see where the ticking
is coming from. Still sounds like a noise problem but if that cap is arcing that may
be the source of the noise.