Which factor can affect the performance of the engine-driven fuel pump?

The performance of an engine-driven fuel pump can be significantly influenced by fuel temperature variations. As the temperature of the fuel changes, its density and viscosity also change, impacting how effectively the pump can move the fuel. Warmer fuel is generally less viscous, allowing it to flow more easily, which can enhance pump performance. Conversely, colder fuel exhibits higher viscosity, making it more resistant to flow and potentially leading to decreased pump efficiency and increased load on the pump.

While fluid viscosity certainly plays a role in the fuel pump's operation, it is closely linked to fuel temperature. Similarly, excess supply pressure can affect the pump's ability to deliver fuel adequately, but is more indicative of system pressures rather than a performance factor directly tied to the pump itself. Incorrect throttle position pertains more to air-fuel mixture ratios than to the fuel pump's operational performance. Therefore, fuel temperature variations stand out as a direct, impactful factor on how effectively the engine-driven fuel pump functions.