This is one of the more popular electronic ignition kits for the MG, as it fits entirely inside the distributor with just two wires running between the distributor and ignition coil.

If you elect to convert your car to electronic ignition, I suggest you put your original points set and condenser and hookup wire in a little plastic bag and keep it in your traveling tool kit, just in case. That prudent move could save you a lot of trouble if the electronics part should happen to fail some time down the road.

This part is available from many British car parts distributors, and may be available from almost any local auto parts store on special order. It may not be in inventory at local parts stores (which is one reason why you should carry your points set in case of failure). You must specify positive or negative ground when ordering. For more information visit the Pertronix web site

This circuit is for Negative Earth conversion only.

The Pertronix Ignitor does essentially the same thing as the original points and condenser, making and breaking the ground connection for the coil. It requires one additional wire to provide battery power to the electronic module. That wire is connected to the power input side of the coil (original white wire connector) for negative earth installation. You can download installation instructions from the Pertronics web site.

Apparently the Ignitor modules for positive or negative earth are the same except for the color of one wire. Being designed for negative earth connection, the positive earth installation must rearrange the wire connections to keep current flowing the same direction through the electronic module. When you order one for positive earth application it comes with one wire in a different color and different instruction paper for installation. Click for Pertronix Negative Earth Instructions or Positive Earth Instructions.

Pertronix ignition can be static timed in the same manner as points ignition. Set the timing mark on the crankshaft pulley to the desired static timing position. Connect a test light to the switched wire running from the coil to the distributor (the one that is not the power wire) and ground the test light. Turn ignition on. Rotate distributor body anti-clockwise until light is out (equal to points closed). Then turn distributor body slowly clockwise just until the light comes on (equal to points open). Lock it down and run it.

If you have trouble getting it to run (usually no spark), then see these documents before you ask questions:   Troubleshooting - - - Module Test

Do not be terribly surprised if the module is just dead. Electronic things do that sometimes, which is why I don't like them in my car. Check the sticker on the back side of module "Ignitor by PerTronix". If the Sticker is shriveled up, wrinkled, cracked, or if you see any burn marks on that side of module, the unit over heated and failed for various reasons.

WARNING: For the Pertronics Ignitor-II model, the installaton instructions state: Warning! DO NOT USE WITH SOLID CORE SPARK PLUG WIRES.

I do not know if this is supposed to apply to the standard Pertronics Ignitor model. I do have a report of solid core HT wires messing up function of the Pertronics-II unit so it doesn't run right, but was okay after changing to resistor wires.

From Barney: -- I have replaced a few Pertronics modules after failure. It is common to find the car sitting on the side of the road on a Sunday afternoon, and the owner on a cell pone trying to figure out where he might buy another Pertronics module on short notice. They are NOT commonly in stock at local auto parts stores, and electronics are not forever, so do carry a spare, or keep the points and condenser and lead wire (parts that were removed) in a baggie in the car for such an occasion. But if you are willing to be re-installing the points and condenser on the side of the road in the dark when raining, I have to ask, "Why did you take them out in the first place"?

On Sep 23, 2018, Jeff Schlemmer of Advanced Distributors in MN, USA wrote:
From my experience rebuilding in excess of 15,000 Lucas distributors, failure rate is at least 50% in the first 3 years of ownership (and that's being generous). I quit selling them 3-4 years ago and I'd bet less than 20% of the units I sold are still functioning. The first step in diagnosing a Pertronix issue is to install points for comparison".