Distributor Cap: How a Motor Works

Series Summary

A distributor cap is an important part of an engine. It has wires that connect to spark plugs which generate electricity that burns gasoline in the combustion chamber and provided power to the engine. When a distributor cap fails, your cars performance does as well. Replacing a distributor cap may seem like a big job but it's easier than you think. In this free automotive video series, let a professional mechanic show you how to replace a distributor cap in a few easy steps. Learn how a distributor cap is an important part of an engine's performance. Get to know what a distributor cap looks like and how to get to the old one and pull it out of the motor. Finally, learn the importance of replacing one wire at a time. You'll feel like a mechanic after watching an expert show you this simple automotive task.

Video Transcript

"Today we're going to show you how to replace the distributor cap and the rotor in your conventional internal combustion automobile engine. On this car, this is a Ford F250, its a V8 motor, it is fuel injected. Now how this motor works is, you have to have three things for the motor to run, really four. One is it takes air. The air comes in through here, goes through the air cleaner and then goes through these tubes into the throttle body. This is kind of like your carburetor. I'm going to point with this screwdriver. This is like your the air comes in through here and then goes down into the motor and is mixed with the gasoline and there is the combustion chamber in there and the gasoline is burned and it makes the car go. Well, the thing that delivers the spark to your motor is the spark comes from the coil. I'm going to point to the coil. This is the coil right here, this little black box makes a big spark of electricity and then the electricity goes through this wire, this is your coil wire, and that coil wire delivers a big spark into your distributor. And then the distributor distributes the spark out these spark plug wires to each of the spark plugs which are in the combustion chamber. So here at the end of my screwdriver, you see the spark plug connector. I'll pull that off so that you can look and see the top of the spark plug. So if you see at the end of my screwdriver, there is this white ceramic insulator. That is part of the spark plug and then this is the spark plug wire that hooks on to the spark plug and then the spark is delivered from the distributor out to the spark plug. Now many times if the car is running poorly or if it just will not start, a common problem is the distributor cap and the rotor."