Pertronix Installation in '73 911E -- complete with photos

[tmctguer]

I finally ended my research on Pertronix points installation and decided to tackle the project. My car is a stock 1973 911E with 2.4 L engine, 3 pin CDI. Here is how I did it:

First, I purchased a used 911 distributor and pre-installed the Pertronix points in the spare distributor ahead of time. I followed the instructions as provided in the box. This included making sure the tab on the bottom of the Pertronix points mated with the hole in the plate that is the pivot point for standard points.



The magnetic rotor took quite a bit of force to fully seat on the shaft of the distributor. In fact, I used an old rotor to get some extra force to ensure the magnetic rotor was properly seated. I used the small clear plastic tool that comes with the Pertronix points to ensure I had the proper gap between the module and the magnetic rotor. Note the top view showing the fit of the module and rotor.


One thing I found peculiar was that the small nuts used to secure the module to the distributor were different sizes, in spite of the two mounting screws being the same size. It took me a few tries on the incorrectly sized nut to figure this out. I also noticed that the small nuts were standard not metric, so I went to my local parts store and bought two small metric nuts to replace them.

Also check out the side view to see how the two units line up.



Next, I had to figure out how to connect the red & black wire from the Pertronix points to the CDI unit. I had decided I was NOT going to cut any existing wires so it would be easy to change back to standards points in the future. I also wanted a “plug & play” installation in case I ever had to change out a failed Pertronix module in the field.
I thought long and hard about how to achieve this and reviewed many posts from RoninLB who had some photos of his set up. I also found the 3 pin CDI installation instructions on the Pertronix technical support page. Well, I had an epiphany last week and realized that I could unplug the 3 pin CDI connector and make short jumpers between the plug and the CDI box. With the right connectors on the jumpers, I could also connect the red and black wires from the Pertronix points to the correct wire.

So here are the photos of the stuff I used to make the small jumpers. Nothing extravagant – just male/female connectors from the local hardware store, plus some butt splices, and 3 way connectors.



I used 14 gauge wire on the short jumpers from the 3 pin connector and the CDI unit and 12 gauge wire to butt splice from the red & black wires of the Pertronix back to the CDI unit. I made sure all my crimps were solid by “pull testing” them.

[tmctguer]

Next, I installed the jumpers from the 3 pin connector to the CDI unit, being careful to match correct color wires (Blue from Pin A, Red from Pin B, and Black from Pin C). I also used care in connecting the 3 jumpers to the 3 male connectors at the CDI box. Since the 3 male pins face downward in a cramped space, it would be easy to cross connections. I tie-wrapped the 3 pin connector to one of the existing electronics in the rear fuse panel. I will cover each of the bare connections with electrical tape just to be safe.



After making all the jumper connections, including a 3 way connector on both the red and black wires, I wanted to test start the engine with my existing set of points in the distributor. By doing a test start, I could tell if my jumpers had caused the car not to start, caused a rough idle, or in any way affected the way the car normally ran. Fortunately, the car started just fine.

Next it was time to put in the distributor with the Pertronix module installed. Before I removed the existing distributor, I rotated the engine’s crank pulley and put the car at TDC



I removed the distributor cap and made sure the rotor was pointing to the small notch in the distributor. I took careful measure of precisely where the front tip of the rotor was relative to the notch in the distributor. If I was lucky, I would not have too big of a timing variance when I restarted my car.



I then disconnected the vacuum advance and the black wire terminal connected to the points/tachometer, and removed the old distributor. I then installed the Pertronix fitted distributor. It took a few tries to get the drive gear lined up correctly to get the front tip of the rotor lined up with the notch in the distributor. I finally got the Pertronix distributor seated correctly and now it was time to route my wires.

For starters, the red & black wires from the Pertronix points are about 12 inches long. I decided that I wanted these wires to follow the existing wiring from the CDI box. So I took some string and fished it through the engine along the wire route. This way, I could cut my red & black wire extentions to match the length of the string. I did this, then installed two butt splices to connect the Pertronix red & black wires to my extensions

[tmctguer]

I then took some 3/8” flexible wire covering purchased at my local auto parts store and fed the red & black wires through it. The only trouble I had was getting the two butt splices to pass through the flexible wire duct. But with some patience, it was finished. I now had a protected set of wires from the exit point of the distributor to the jumpers connected to the 3 pin connector.





I connected the ends of the red & black extensions to the 3 way connectors I had spliced onto my red & black jumpers connected to the CDI Box. I wrapped the 3 way connectors with electrical tape to prevent them from shorting out should they touch each other. The female connectors were already shielded.



With the rear fuse panel re-installed, you cannot tell any work was done.



At this point, all that was left to do was cross my fingers and try to start the car. I had my timing light ready so I could re-time the car with the newly installed distributor.

Lo and behold, the car fired right up. It idled a little rough at first, but after some slight timing adjustments, the car ran fine. I got the timing set at 5 degrees ATDC at 1000 RPM. I let it idle for a few minutes in the garage and wiggled all my wiring around to see if anything odd happened. Everything was holding so I took the car out for a spirited test drive. The car ran well in all RPM ranges. It had an extremely smooth idle at stop lights. I was very happy with the results.

Now, I plan to install my extra set of Pertronix points in my original distributor. I will use this as a working spare. I will probably expose the butt splice locations within the flexible wire duct in order to make a field change of the distributor that much quicker. That is, by exposing the butt splices, I will just have to run the red & black wires to that point in the wire loom rather than all the way back to the CDI box wire jumpers.

As an added step, I plan to get some small labels and affix them to all wiring I installed so that all wires are clearly marked (e.g., “Pin A, Blue/Yellow, Positive Coil”, “Pin B, Red, Power”, Pin C, Black, Points/Tach”).

So thanks for all who have posted in the past about your Pertronix & MSD installations. I learned from many of them and wanted to repay the favor by posting my experience. Any comments or questions would be appreciated.

[tmctguer]

a couple of more photos I forgot to post.

Here is one showing the 3 Pin Connector unplugged from the CDI unit:



Here is a photo of the jumpers connected to the 3 Pin Connector:



and finally, here are the 3 way connectors used to connect the red & black wires from the pertronix into the red & black connections between the 3 Pin Connector and the CDI unit:

[haycait911]

look here
broken ignition rotor, why?

make sure your rotor is completely seated, ie; a gap between it and the pertronix wheel. ( especially with a rev-limiting rotor)

other than the above problem I'm a big fan of the pertronix system. always use one.

[tmctguer]

posting a pic of the correct 3 Pin CDI wiring diagram from the Pertronix site.

[RoninLB]

I used blue loctite to hold the module