What troubleshooting steps should be taken for an engine that will not start?

When troubleshooting an engine that will not start, checking for fuel delivery and spark is a critical step. Both fuel and spark are essential components of the combustion process that powers an internal combustion engine. If either is missing or insufficient, the engine will be unable to ignite the air-fuel mixture, resulting in a no-start condition.

Ensuring that the fuel system is delivering the proper amount of fuel to the engine involves checking the fuel pump, fuel filter, and fuel injectors. Simultaneously, verifying that there is a sufficient spark from the ignition system ensures the combustion of the air-fuel mixture. If both of these elements are functioning correctly, then further troubleshooting can be directed towards other components such as the engine timing or compression.

This choice directly targets the core components responsible for starting the engine, enabling effective diagnosis of the issue at hand. In contrast, evaluating tire pressure, brake fluid levels, or the air conditioning system does not directly impact the engine's ability to start. These systems, while important for vehicle operation, are not relevant in diagnosing a no-start condition pertaining to engine functionality.