Ok so i installed the Pertronix Ignitor II on my car a month or so ago and it seemed to run fine. But last week it ran like crap, and we checked it and two cylinders wern't firing. On the distributor cap these two plugs are right next to each other. So we thought it was the spark plug leads, so we replaced those but it did the same thing. Then later it was running on only 4 cylinders! the four that were out were the front half of the cap, all in a row. weird we thought. So we (my dad and I) determined the ignition went out already so I took it back and got it exchanged with no problem.

I install the new Pertronix system, set the gap, do everything according to directions. Fire it up and only 7 cylinders are firing. It is not the plug, or the wires or anything like that because the lead itself gets no power (we used a timing light). We determined that it is the magnet ring that goes on the distributor cam that is now defective (maybe). We know it is this because if you rotate the magnet ring to a different possition, then a different cylinder won't fire.

So whats the problem? Is it simply another defective pertronix unit that we got? Just the magnet ring?

One thought I had was to set the air gap between the unit and the magnet ring even closer than it is, thinking that it isn't picking up on the magnet well which is what is causing the misfire. Another thought is that our distributor could be bad? As far as we know it is the original distributor.

Any advice is appreciated! thanks

 

prollu the mag ring cause if it picks up other cyls then the unit is working just not the mag ring i went with the crane xr-i it was great especially with the built in rev limiter

 

Put the points back in it and check to see if all cylinders fire. That can rule in or out the Petronix. I have heard that the II model was problematic when introduced a couple years ago. You might have gotten a couple of those. Find the first generation Petronix. I have had this one on my CJ for 6 years now, no problems at all.

 

Check the articles about installing pertronix in the FAQ section. I don't know if this is your problem or if you did this already, but When I put in my pertronix. (mine is a pertx1) I had to bypass the resistor wire by installing a wire directly from the ignition switch to the coil. The pertx like higher voltage. Also don't make the mistake I did at first and ran the wire on top of the intake manifold. It doesn't like the heat.

 

Ok so I put the points in today (engine never running on points since rebuild) and fired it up and all cylinders are firing. Man is it beast! Definitely a strong engine.

So basically the problem has to be the pertronix ignition. The pertronix instructions say to set the air gap to .030, but do you think it could work better if I set it to the points setting which is .017? My only thought was that if the air gap was smaller, then maybe the magnet would be picked up on better.

We're thinking of just returning the pertronix and maybe going with Crane xr-i ignition system as Brandontyler65 suggested. It seems like it will work nicely, and that rev limiter would never be a bad idea.

any suggestions?

 

Return the pertronix and have them give you a new one. The little clear plastic gauge should be used to set the distance from the module to the magnet. There are literally thousands of pertronix systems out there that are working perfectly. Mine hasn't missed a beat since I put it in.

 

May want to consider new distributor - MSD Ready to Run nice choice and not too expensive. Put one in my car and runs great - had Pertonix for awhile but started to have problems with vaccum advanced (not related to Pertonix) and decided for piece of mind might as well swap out the 40 year distributor.

 

If the car runs strong with the points, why would you suggest changing out the distributor? The distributor is not the problem, and you know my theory. "If it ain't borke, don't fix it."

 

Is it possible that the top bushing/bearing on the distributor is worn out?

If so it might be possible that there is enough "shaft wobble" to effect the proper "reading" of the magnetic signal?

It is my understanding that bearing wear in distributors is really how they wear out.

Might be that with the points in the distributor, that the tension in the points spring keeps the the "wobble" in check, or that the points are not as sensitive to this wobble as the electronic device is.

I would remove the distributor and check for any side to side wobble of the shaft, both the top and the bottom bearing, and check for excessive verticle movement of the shaft as well.

The chances of both the first unit and the replacement unit suffering from the same problem seems to be remote. Considering that only specific cylinders seem to be involved,the only common denominatorseems to be the distributor, and wear is the only issue that I can think of that might cause this action.

Power supply still could be an option, but I don't think so when the symptoms are considered, butyou didreplace the power "resistor wire" running to the distributor right?

 

Suplimental to previous post.

OR could there be oil or graphite in the distributor cap?

This might cause the spark to "jump cylinders" Remote, but might be possible.