What is the ignition system component that creates a high-voltage spike for the spark plug?

The ignition system component responsible for creating a high-voltage spike for the spark plug is the ignition coil. The ignition coil converts the battery's low voltage (typically 12 volts) into a much higher voltage, often in the range of 15,000 to 45,000 volts or even higher, which is needed to create a spark at the spark plug. This spark is what ignites the air-fuel mixture in the combustion chamber of the engine, leading to engine operation.

While the coil pack, which is a modern variation of the ignition coil, can perform a similar function and contribute to multiple cylinders, it is still fundamentally an ignition coil design split into multiple outputs. The components like the distributor cap serve to distribute the high-voltage spark generated by the ignition coil to the correct spark plug in older ignition systems. The fuel injector, on the other hand, is responsible for delivering fuel into the combustion chamber and does not have a role in the ignition process.

Understanding that the ignition coil's primary function is to create that essential high-voltage spike clarifies its critical role in the ignition system of gasoline engines.