The distributor cap is a critical device within you vehicle’s ignition system. Effectively, its purpose it to transfer the charge created by the rotating of the distributor shaft and the rest of the motor. The distributor cap takes that energy and uses it to power the engine’s cylinders at the appropriate time and order. As a critical portion of your ignition, it should be inspected whenever you’re having problems with the ignition, as well as on the pre-scheduled maintenance times, which can be found in your car’s manual. Distributor caps are pieces of your car that need to be fixed at certain times, and even if you find a problem in other components of the ignition system, there is a chance that your cap will need changing too.
Changing your distributor cap is a fairly easy job, and it can be done by somebody with even a low understanding of car parts or tool aptitude. It’s not as easy as unscrewing and re-screwing the cap, unfortunately, but it is a job that can be done with the most basic tool set, and one that can be completed in around an hour.
If you’re trying to check, remove or change your distributor cap (or the spark plugs), you’ll find it attached to any of the spark plug wires. These wires are located all around your engine, and should be easy enough to find. One end will be connected into the engine, and the other into the distributor cap, but it should look like it simply goes into a hole that is located near the engine. This is because you usually can’t just get to the distributor cap in most vehicles – normally, the air intake system will be in the way. You’ll probably have to remove the air intakes system, or at least some part of it, in order to get to the distributor cap.
Now, you probably won’t have to take off the entire air intake system, as the cap is fairly small, and should only be underneath one part of it. Nonetheless, removing any part of the air intake is going to be fairly easy, as it is bolted down. As long as you have a decent wrench, getting the bolts on should be no problem, although you’ll want to memorize what order you take the out in just in case. Once you unbolt the intake, it should pop right off, leaving the distributor cap uncovered. The plugs should be connected directly to it. In any case, it will be circular, facing sideways, and probably colored differently than the rest of your engine.
Before you detach the spark plugs, you’ll need to find some way of memorizing their appropriate spots. Each spark plug is attached to a cylinder on one end, and a corresponding slot on the distributor cap; whether you’re replacing a plug or the cap, you’ll need to make sure that the plugs maintain the same cylinder to cap position, otherwise, the cylinders that you’ve misplaced will no longer work.
Next, you’ll need to remove the spark plug wires and ignition cables. In some cars, you’ll have to remove other pieces of the engine in order to get to the ignition cables properly, but it shouldn’t be very hard to find out what that is and remove it. To remove the plugs, just twist and then pull them out. Remember to twist first! Otherwise you can damage the rubber cable, as it can stick to the plastic.
To remove the distributor cap, just unbolt it (or unscrew or unclip, as the case may be), take off any remaining wires, and slide the cap off the engine carefully (some parts of the engine that the cap is connected to are very fragile). To install a new cap, simply replace the rotor an cap, and then reverse your steps.