What does an engine control unit (ECU) control in the fuel metering system?

The engine control unit (ECU) plays a critical role in the fuel metering system by managing various aspects of engine performance, primarily focusing on the fuel mixture and timing. In this context, the fuel mixture refers to the ratio of fuel to air supplied to the engine for combustion, which is vital for achieving optimal performance and efficiency. If the mixture is too rich (too much fuel relative to air), it can lead to inefficient combustion and increased emissions. Conversely, a mixture that's too lean (too much air relative to fuel) can cause poor performance and potential engine damage.

Additionally, the ECU is responsible for controlling ignition timing, which is the precise moment when the spark plug ignites the air-fuel mixture in the combustion chamber. Proper ignition timing is crucial for maximizing power output and minimizing emissions. By adjusting both the fuel mixture and the ignition timing in real-time, the ECU ensures that the engine operates efficiently across various conditions, such as changes in load, speed, and temperature.

Furthermore, controlling only the fuel pressure or solely determining the type of fuel used does not encompass the full scope of the ECU’s capabilities. The ECU's ability to adjust both the air-fuel mixture and the timing represents a holistic approach to engine management, making the correct