An ignition system uses electricity from a vehicle’s battery, increases the battery voltage significantly, and then sends this high voltage to the spark plugs. The spark plugs produce a spark that ignites the air-and-fuel mixture that’s been compressed in an engine’s combustion chamber. The resulting burning of the fuel in the combustion chamber forces the piston down and gets the crankshaft turning. Because an ignition system performs such a vital function, it’s important to keep its components in working order. Any defect in the ignition system can result in a loss of engine power, a reduction in fuel mileage, and even engine failure. For this reason, the tune-up of a vehicle’s ignition system is one of the most important procedures performed on an automobile. An ignition system tune-up usually involves the inspection, adjustment, and replacement of all the ignition system components, especially the spark plugs.
The servicing interval for ignition system components differs from vehicle to vehicle. The vehicle’s service manual usually contains a section that lists the recommended servicing interval for a particular vehicle’s ignition system. This section is called the maintenance schedule. The maintenance schedule contains information such as how often spark plugs, oil, and oil filters should be changed.
As you know, several basic types of ignition systems are used in automobiles. Because of the variations in the components that make up these systems, the procedures differ slightly from system to system. Let’s begin by discussing how to service the components common to all ignition systems—the spark plugs, ignition coils, and spark plug wires.
