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Distributor Cap

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The distributor cap is a device in the ignition system that distributes electricity from the ignition coils to the spark plug wires at the right timing. It is usually made of hard plastic and a small amount of copper. Inside the distributor cap is the distributor rotor, which rotates as it receives current from the ignition coils and passes it on to the copper portion of the cap, which then passes it on to the spark plugs.
A distributor rotor also has a metal component which allows it to connect with the cables of the spark plugs of the cylinders in the engine. The rotor is mounted on the upper end of the distributor shaft, where two screws attach the rotor to a plate on top of the shaft. The rotor has built-in locators that fit snugly into the holes in the plate so it will not fall off. A centrifugal advance mechanism drives the rotor as it turns on the camshaft.
Because the distributor cap is bombarded with high voltages all the time, it must be inspected and replaced regularly. Otherwise, carbon tracking will develop in the cap and might cause misfires in the engine. Auto experts suggest replacement once in two years or every 15,000 miles of distance traveled. Owners of older vehicles should be more wary, as their caps and rotors are more prone to wear out.
The best way to check if your distributor caps and distributor rotors are working properly is at night, because you can easily see the lights that they give off from the current. You should not touch them, though, because they have as much as 20,000 volts running through them.

Distributor Cap Articles

  • Important Facts You Need to Know About Distributor Cap 10 October 2012

    Ensure a proper flow of high-volt electricity by supplying your distributor with a heavy-duty distributor cap. Purchase this product now/
    There so many systems inside your car and each of them have their own specific function to fulfill. One of these systems is the ignition system. The ignition system works by providing the engine with the power to start and maintain the combustion process. And everybody knows that for your car, no combustion means no power. Such is the importance of the ignition system, and that's why you should maintain its parts. One of these ignition parts that you should look after is the distributor cap.
    This ignition component consists of terminals used to transmit voltage to the engine's spark plugs. The transmitted voltage is regulated by the distributor cap rotor and is used to burn the air and fuel mixture to power the engine. Plus, this cap also provides covering for the distributor so no dirt, dust or moisture can enter it.
    Once your distributor cap wears out, the performance of your ignition system will be affected. Dirt and moisture will make its way inside the distributor and its operation will be compromised. So you better take good care of this ignition component and make sure it gets the care it deserves from you. And if you need a replacement distributor cap rotor, you should get one immediately.

  • Distributor Cap: Just the Facts 03 October 2012

    One vital component in your vehicle's engine is the distributor cap. Designed to withstand heat and pressure, the distributor cap's primary function is to cover the distributor and its rotor. More importantly, though, the distributor cap contains the terminals through which electric current from the distributor rotor passes to the spark plugs. The distributor cap must be regularly checked to find out if the sparks are arcing from point to point within the cap. Problems with distributor cap can be verified through visual inspection. Inspect for cracks and breaks on the cap itself and on the terminal towers, as well as for gray carbon tracks. While the cap is removed, check the interior for carbon tracks and deposits and for signs of corrosion. If the damage seems too great for simple repair, your best option is to get and install a new distributor cap. Auto Parts Deal offers the best distributor cap for your specific vehicle model.


    • A distributor cap from us works more efficiently, ensuring quicker, more successful start-ups.

    • Our distributor caps can endure damaging pressure and heat for longer periods, so you won't have to worry about getting a replacement.

    • Our distributor caps are designed to fit most distributor models.