Pertronix vs. points on my 71 240z. Here's my story.

[rubrbulits]

After I bought this car a few years ago the first thing I did was get the engine tuned as perfect as I could. The previous owner never had it running, but claimed the engine was rebuilt when he bought it. I believe this is true since the compression test i later did proved this is a new rebuild. Anyway I started with the complete carb rebuild kit with video from Z Therapy. New plugs, wires, cap, rotor, and the Pertronix kit with 3.0 ohm Flame Thrower coil. Of course the gas tank was full of gunk, ALOT OF IT, so I ran fuel from a gas can as I got the engine running and tuned perfect. I managed to get the gas tank mostly cleaned, but I still had to change filters about every 50 miles once I started using the tank. I drove this car for one summer, mostly on the weekends and it ran great, except for the fuel filter clogging often. I've spent the last two years stripping ALL of the paint to bare metal and etching priming it to prepare it to go to the body shop. I also pulled the engine and transmission so I could paint the engine compartment so the body shop wouldn't have to deal with that. Now the engine and transmission are back in the car and when I first got it to run it ran very good. But, all of a sudden it started running rough and wouldn't rev past about 4200 RPM. I noticed alot of threads on the subject of points VS Pertronix, so I decided to put the points back in to see what would happen. Well, installing the points made a difference. It revs all the way. I'm not saying one or the other is better, I just wish I knew why this happens. I've read numerous threads where people go back and forth on this subject, but no one seems to have a difinitive reason why this happens. Like I said, the Pertronix worked great at first. So anyway, this is my story and my 2 cents. Just wish I knew why.

[Oiluj]

I run a Pertronix and would never go ack to points.

Verify that all the wiring on you pertronix set-up is in good shape, and that there are no possible shorts to ground. When I was having ignition problems on my MG, I found that there was a worn spot on the wire, (insulation), that allowed the wire to contact the distributor case when the distributor plate rotated. This caused a similar symptom to what you describe.

[Arne]

The reason there is no definitive answer is that there are several different potential causes for this particular symptom. In my case, the root cause was a condenser attached to the negative terminal of the coil. My Pertronix has not missed a beat since I removed the condenser.

[rubrbulits]

Yes, I agree. I just drives me nuts when I solve a problem and don't really know why. The Pertronix worked perfectly when I originally installed it. But when I put the engine back together a few years later, there's a problem. There's a perfectly good reason for this. I just hope I can figure it out. I still have all of my Pertronix parts in a zip-lock bag ready to be re-installed when I get this figured out.

[BadDog]

This probably isn't the case since your Pertronix hasn't had much use, but check the plastic "tape" around the Pertronix ring that goes beneath the rotor. If one of the magnets has come out, you will experience the symptoms you've described. Ask me how I know ;-)

[rubrbulits]

Yes, I checked that too. All magnets are there. Thanks.

[Arne]

I had to do a piece by piece troubleshooting routine to Identify my issue. I had played with it several times prior to that without success. Check out this thread, starting with post #82:

http://www.classiczcars.com/forums/showthread.php?37900

[Reverend]

Heard a lot of bad things and good things about pertronix. I bet there is some electric engineer (like Dave) in your area that can make custom electronic dizzy. Mine is custom, and it cost me only 60€ (80$) Parts itself dont cost a thing, only the labor does.

[rubrbulits]

Another issue I had besides the rev issue was a rough overly rich idle. It turned out my rear carb piston wasn't dropping all the way. After I fixed the carb issue it ran PERFECT! But just to make sure, I pulled the points and re-installed the Pertronix. Still, it wouldn't make it past 4300 RPM. I put the points back in an it runs fine. Like Arne said, there are usually other things going on and the carb was definately the other thing.

[gnosez]

Going on 11 years with my Pertonix set-up and no issues whatsoever (I did remove the ballast resistor and have an MSD box as well).