Electric Fuel Pump - Lifan 620 Maintenance Manual

7. Electric fuel pump

(1) Function: To deliver fuel in the oil tank to the engine with a certain oil pressure and volume,
not greatly affected by temperature and voltage.
(2) Structure and principle: The fuel pump consists of DC motor, vane pump, and end cap
(integrating check valve, pressure release valve and anti-electromagnetic interference element),
which shares the same axle and housing with the motor. The bump and motor in the housing is
surrounded by gasoline, which can be used for cooling and lubricating material. The battery
supplies power for the electric fuel pump through a relay. The relay is connected with the fuel
pump only when the engine starts and operates. When the engine stops due to some troubles, the
fuel pump will stop automatically. The maximum pressure at the outlet of the fuel pump will be
decided by the pressure release valve. As no-oil-return system is adopted, the fuel pressure
regulator is installed on the fuel pump assembly. The fuel pressure regulator can adjust the
pressure of the fuel pump to 380 kPa to meet the demand of the system.
(3) Connection of the wiring diagram (Fig. 1-12)
Notes: The temperature of the fuel greatly affects the performance of the fuel pump. When
operates under a high temperature for a long time, the pressure of the fuel pump will decrease
sharply. Therefore, if the engine fails to start up after warm-up, please carefully check the fuel
pump for working performance under a high temperatue.
www.CarGeek.ir
(Fig. 1-11)
Fig. 1-11
Fig. 1-12
32
www.cargeek.ir