The ignition system

Standard E-Types run a conventional contact-breaker ignition: a distributor with points and a condenser, a coil, and plug leads. The system is simple, understandable and entirely dependent on the condition of a few small parts and the accuracy of one setting.

The wearing parts

• Points erode and their gap drifts, which changes the dwell and the timing together. A car that slowly loses its edge between services is often a car whose points have wandered.
• The condenser fails slowly or suddenly; its failure shows as a weak spark and pitted points.
• The distributor cap and rotor track and crack; the leads age and leak their spark to earth in damp weather, which is why a bad-weather misfire points here first.
• The mechanical and vacuum advance mechanisms stick with age, and a distributor whose advance has seized makes the engine flat and thirsty without any single dramatic symptom.

Timing before carburation

Ignition timing that is retarded or incorrect puts heat into the engine and takes power out of it, and no carburettor adjustment will compensate. This is why setting the timing belongs at the start of any tuning session, before the mixture is touched. Static timing with a lamp gets the engine running; checking the advance curve through the rev range is what makes it right.

Electronic conversions

Electronic ignition kits replace the points and condenser inside the original Lucas 22D6 or 25D6 distributor with an optical or magnetic trigger module. Kits such as those sold under the AccuSpark, PerTronix Ignitor and 123ignition names are common; they are mentioned here as examples of what is available, not as recommendations.

What the kit actually does

The distributor body, cap, rotor, plug leads and coil remain in place. The module switches the coil at the right moment by reading a trigger inside the distributor, which removes the rubbing block, points gap and dwell from the maintenance list. The advance curve is still produced by the distributor's mechanical and vacuum mechanisms, and the ignition timing is still set at the engine in the normal way.

What it does not fix

• A cracked distributor cap, a worn rotor or old plug leads will still break down, and a bad-weather misfire will still point to the high-voltage side first.
• Incorrect static or dynamic timing will still make the engine flat, hot and thirsty. The kit must be timed after fitting.
• A seized or sticky mechanical or vacuum advance will still rob performance. The distributor still needs to move freely.
• Some kits need the correct polarity and a good earth at the distributor body. Others need the coil or ballast resistor to match the module's requirements.

Fitting notes

The change is reversible if the original points plate, condenser and screws are kept. Set the timing after installation, do not assume the kit arrives at the correct relationship, and earth the module to a clean point on the distributor or engine. Most reported problems come from poor earths, incorrect coil resistance or the assumption that electronic ignition removes the need to check the timing.