Introduction #
As the title confirms this is my own experience of Adding Pertronix Electronic Ignition to a Lucas 25D distributor. Points were a new concept, to me at least, when I got my 72B. I had wanted to understand them and had successfully updated the points. Also I finally understood the method for adjusting the gap. I must have done it fairly well because the car starts, as it should, with just a bump of the key. However, the car wasn’t running that great and I had a slight misfire. To try and address this, I bought a Pertronix Ingnitor® electronic ignition module.
As it turned out the misfire was apparently due to having the wrong coil installed. It may also have been contributed to, by a failing (rusty pin holes) and badly connected exhaust down pipe. Anyway, although I’m no points expert since I had already bought the Pertronix, LU-142A is the part number for a 25D (available on Amazon, click here), I decided there was no reason not to put it in and save the points just for emergencies. What follows is a pictorial flow of the installation process I followed.
Background #
I did have some experience with a Pertronix as I have one in my 77B which has the Opus 45DE4 distributor. However, that’s different because that was always electronic. Also it doesn’t install quite the same and the wiring is different to address the ballast resistor etc.
Do you feel you need a new distributor? If yours is worn, shaft wobble, non functioning vacuum advance etc. then there is an alternative to new. I can personally recommend Jeff Schlemmer of Advanced Distributors (see www.advanceddistributors.com). He has a great service and can setup the vacuum advance curve to match stock or customized engines/setups. He does great work and is a regular advisor on MG Experience. Your distributor will come back looking brand new and Jeff can install a Pertronix for you if desired. He now seems to prefer points though.
Step By Step – Lucas 25D Distributor – Adding Pertronix Electronic Ignition #
Review the following images and notes to accomplish this project.
Step 1 – Remove Points #
Here’s my starting point after removing the distributor cap. You need to remove the points and the first thing to do is to remove the nut holding the wires in place. Also remove the white/black wire that comes from the coil to the distributor.
Step 2 – Removing Wires & Insulator #
With the nut removed lift the plastic insulator/spacer top piece to access the wires. This will allow you to remove the wire to the condenser and to also remove the wire/plastic connector that brought the connection from the coil to the points.
Step 3 – Points Fully Removed #
In this picture the points are removed. I removed the large flat head screw at the top edge and the Philips screw at lower left that was also securing the condenser.
Step 4 – Mounting Plate #
At this stage I have installed the mounting plate from the Pertronix kit. It fits perfectly and the Philips screws are provided as part of the kit. Tighten both of these securely. Note the mounting posts this plate provides for the Pertronix module.
Step 5 – Install Ignitor Module #
The Ignitor module is just sitting on the locating posts. The rubber fitting, made to fit, is in place allowing the wires to pass to the outside of the distributor. Be careful with the rubber fitting to make sure you locate it correctly. It’s shaped like the plastic piece it replaces.
Step 6 – Secure the Ignitor Module #
Here I have simply secured the Ignitor module with the provided lock nuts that are in the kit. I used a 5/16th nut driver and made sure these were really secure—enough to move the plate/advance mechanism.
Step 7 – Secure the Wires Away From the Rotor #
I have secured the wires of the Pertronix to the distributor plate using a tie wrap. The kit provides a lock tie, but this is easier if you need to remove the unit. It’s really important to ensure the wires cannot get caught up but have slack enough for the vacuum advance!
Step 8 – Install Magnet Onto Distributor Shaft #
Now you can see the magnet piece fitted over the distributor shaft. The inside of this is shaped to fit the shaft perfectly. So, if it doesn’t seat fully just rotate it and try again. It must fully seat itself and leaves room for the rotor.
Step 8 – Install the Rotor #
Here the only change is the rotor being installed. As I’m paranoid about the wires getting caught up (previous bad experience). So, I checked on them several times during testing. But remember to always to put the rotor back on before trying to start the car! 🙂 Less anxiety. Hopefully this process for a Lucas 25D Distributor – Adding Pertronix Electronic Ignition helped.
Step 9 – Coil & Other Wire Management #
Connect the black Pertronix wire to the negative side of the coil. Remove the white/black wire from the harness connection. Tie up/secure the white/black wire connections (from coil and distributor) as they will no longer be needed. Keep them safe in case you need to go back to points at some stage (planned or unplanned). The red Pertronix wire goes to the positive side of the coil. Put the distributor cap back on (make sure the rotor’s in place) and fire up and test your handy work out!
Other Materials #
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