What is a fuel pump?

The fuel pump is a pump used in the fuel supply system to overcome the hydraulic resistance of the fuel filter and stabilize the amount of fuel supplied to the high pressure pump when the hydraulic pressure of the filter rises due to dirt. The flow rate of the fuel pump must be at least 2+3.5 times the maximum fuel supply of the engine to ensure that the high-pressure pump can work stably even when the filter is dirty and the resistance is large.

The fuel pump is driven by the high-pressure pump shaft or the engine. In some systems, electric powered pumps are used to make auxiliary pumps. There are many different types of fuel pumps, such as piston type, diaphragm type, gear type, rotor-vane type, etc. The most commonly used type of fuel pump is a double-acting piston fuel pump with automatic piston stroke change. This pump is usually fitted with a hand pump to remove air from the system prior to start-up. The advantage of a plunger pump is that it maintains a high supply coefficient in low speed mode, and component wear has less effect on pump performance than other types.