What determines the amount of pressure required by a hydraulic injector?

The amount of pressure required by a hydraulic injector is primarily determined by the pressure developed inside the cylinder during compression. This pressure is crucial because it directly influences the injector's ability to deliver fuel into the combustion chamber at the necessary timing and volume.

When the cylinder compresses, it creates a specific pressure environment that the injector must overcome to inject fuel effectively. If the pressure inside the cylinder is high, the injector must generate a corresponding higher pressure to ensure that fuel is atomized and injected efficiently. This relationship between cylinder pressure and injection pressure is a critical aspect of achieving optimal combustion and engine performance.

Other factors, such as the size of the injector orifice, fuel viscosity, temperature, and the output pressure of the fuel pump, play roles in the overall injection process but do not dictate the fundamental requirement for pressure to inject fuel against the existing conditions created by cylinder compression.