Which pump in the fuel system feeds the engine-driven high pressure fuel pump?

The engine-driven low pressure fuel pump plays a crucial role in the fuel system by drawing fuel from the fuel tank and supplying it to the engine-driven high pressure fuel pump. The low pressure fuel pump is designed to operate at a lower pressure and is responsible for ensuring a consistent flow of fuel to the high pressure fuel pump, which then pressurizes the fuel before it is delivered to the engine.

This arrangement is vital for maintaining the proper fuel delivery required for efficient engine operation. The high pressure fuel pump cannot operate without a reliable input from the low pressure fuel pump, making the latter a fundamental component in the fuel system.

The other components mentioned, such as the transfer jet pump and the primary fuel pump, serve different purposes within the fuel system. For instance, the transfer jet pump is typically used to assist in moving fuel from one section of a tank to another or to help maintain fuel supply under specific conditions, while the primary fuel pump (if referring to an electric pump) usually integrates with the fuel system but has a different operational function than the engine-driven low pressure fuel pump.