An ignition coil rubber boot serves several important functions.

Firstly, it provides insulation between the ignition coil and the spark plug, preventing electrical leakage and ensuring a proper electrical connection. This helps to deliver a strong spark for efficient combustion in the engine.

Secondly, it protects the connection from moisture, dirt, and other contaminants. By creating a seal, it keeps these elements out, reducing the risk of corrosion and damage to the ignition system components.

Finally, the ignition coil rubber boot also helps to reduce electrical interference. It acts as a barrier to external electrical signals that could disrupt the operation of the ignition system. This helps to ensure smooth engine performance and reliable starting.