What are the reasons for a car not starting when the battery is fine?

[DiIsabella]

If the battery has power but the engine cannot be started, it may be due to issues with the engine's ignition system or fuel supply system. At this point, it is necessary to read the fault codes, locate the faulty component, and then replace it. More relevant information is as follows: Note 1: When starting a car engine, both the ignition system and fuel supply system need to function; otherwise, the engine cannot start. Spark plugs and ignition coils are the main components of the engine's ignition system. Spark plugs are wearable parts that require regular replacement. If not replaced for a long time, the electrode gap of the spark plug will increase, affecting its ignition energy. Additionally, carbon deposits may form on the electrodes, further impairing the spark plug's ignition performance. Note 2: The ignition coil's role is to convert 12V voltage into tens of thousands of volts. It is directly connected to the spark plug to ensure sufficient ignition energy. If the ignition coil is damaged, the spark plug cannot ignite properly. Although the ignition coil is not a wearable part that requires regular replacement, prolonged operation in high-temperature environments can easily lead to failures.