FAA Powerplant Written Practice Test

During which engine stroke does a continuous cylinder fuel injection system typically discharge fuel?

1. Only during the intake stroke

2. Only during the compression stroke

3. All continuously

4. Only during the power stroke

The correct answer is: All continuously

A continuous cylinder fuel injection system is designed to discharge fuel into the engine's cylinders continuously rather than at specific intervals or during specific strokes. This approach allows for a more consistent fuel-air mixture, which can enhance performance and efficiency, particularly at varying engine speeds and loads. The continuous nature of the injection helps ensure that fuel is always available for combustion as the engine operates, regardless of the specific engine cycle stage. In contrast, other methods of fuel injection typically deliver fuel only during certain strokes, such as the intake or power stroke, emphasizing the advantages of continuous injection in providing a more stable and reliable performance across different engine conditions. This continuous injection is particularly useful in applications where precise control of the air-fuel mixture is critical for optimal engine performance.