What must the secondary voltage be sufficient to do in an ignition system?

In an ignition system, the secondary voltage must be sufficient to jump the spark plug gap and ignite an air/fuel mixture. This is crucial because the spark plug gap is designed to create a high-voltage arc that ignites the compressed fuel and air mixture in the combustion chamber. The ignition coil generates this high voltage, allowing the spark to bridge the gap between the electrodes of the spark plug.

If the secondary voltage were insufficient, the spark would either be too weak or nonexistent, leading to incomplete combustion or failure to start the engine. The ability to jump the gap effectively is vital for optimal engine performance and efficiency, ensuring reliable ignition under various operating conditions, including idling and higher speeds.