Ignition Distributors & Parts

A Proper Distribution of Power

Distributors are an essential component of your vehicle's ignition system. An automotive distributor is an electro-mechanical device that routes high voltage output from the ignition coil to the spark plugs, which then ignites the fuel in the engine cylinders. The distributor must accurately trigger and distribute the ignition spark time-delivery to each cylinder at the precise moment it is required for the ignition system to function properly.

The car distributors ignition systems are composed of several key components:

• Housing
• Distributor cap
• Rotor
• Condenser (for older vehicles)
• Ignition coil (for GM HEI and similar designs)
• Points (for older vehicles)

The housing is the main body of the distributor, keeping all the main components together. The cap is attached to the top of the housing and provides a connection point for the spark plug wires. The rotor is located beneath the cap and spins as the engine turns. As it rotates, the voltage arcs towards the correct spark plug wire, transferring the current to the wires. The ignition coil transforms the low voltage from the battery into the high voltage needed to create a spark. Finally, for older vehicles, the points are small metal contacts that open and close as the distributor rotor spins, controlling the timing of the spark.

Certain configurations feature an ignition control mechanism known as a distributor vacuum advance system. These parts use the vacuum created by your engine and consist of a canister, diaphragm and plate. When you accelerate, the pressure increases and the diaphragm inside the canister engages a plate that advances the ignition timing.

Distributors and their parts make up an intricate and sophisticated system. Due to the volatile environment in your engine bay and their constant delivery of high-voltage currents, these parts tend to wear out easily. The experts at NAPA can help you understand the symptoms of a failing distributor or distributor parts, how to fix them and troubleshoot current issues and even avoid future engine problems.

When You Can't Quite Ignite

It is alarming when your auto distributor parts start failing and ignition problems start occurring. If you press the accelerator at a green light and your engine hesitates or feels like it's losing power, if you notice a decrease in your fuel economy or if it is difficult to get your vehicle started, you are possibly dealing with a failing distributor. Other symptoms include rough idling, stalling and decreased power.

While electronic distributorless ignition systems have replaced the traditional distributor and its components in more modern vehicle designs, the older systems still require a little more TLC. Regular maintenance, such as replacing the distributor cap and rotor, can help prevent these issues and prolong the distributor's life.

Check, Clean & Maintain Your Distributor Cap

Using a flathead screwdriver, gently pry off the brackets from your distributor cap. Check the metal of the contact points for any corrosion or buildup. Using electronic parts cleaner, spray these contact points. Use PB Blaster or another type of penetrant on hardware like the point plate and any bushings, screws and springs. Make sure everything is dried well with a rag or paper towel.

Inside the distributor housing, clean off all electrical contacts and dry thoroughly before reassembling. Check the distributor felt plug for corrosion and replace it if necessary; make sure not to get any oil on the felt. Once all the parts are clean and dry, reassemble the distributor housing carefully.

While you're under the hood, check all your spark plugs and plug wires, ignition coils and starter solenoids plus ensure that all battery cables and terminals are clean and corrosion-free. If you still have ignition issues or you just don't have time to get the spark back in your ride, don't worry! There's a conveniently located NAPA Auto Care Center near you staffed with ASE-Certified technicians ready to get your ride started and running like new. Check out the budget-friendly Repair Estimator Tool so you can confidently get your car distributor repairs under way.