Fuel Pump Damage Detection Method
1. Inspection of the working condition of the electric fuel pump
The inspection method is to first short circuit the two detection sockets on the fault detection socket with a jumper wire, and then turn on the ignition switch (do not start the engine). At this point, you should be able to hear the sound of the fuel pump running from the fuel tank. If you cannot hear the sound of the engine running clearly, you can pinch the gasoline hose with your hand and feel the fuel pressure. Otherwise, it indicates that the electric fuel pump is not working, and the power fuse, relay, and control circuit of the electric fuel pump should be checked for faults. If everything is normal, the electric fuel pump should be disassembled and inspected.
(1) Use a dedicated wire to connect the fuel pump test terminal on the diagnostic socket to a 12V power supply;
(2) Turn the ignition switch to the "ON" position, but do not start the engine;
(3) You can hear the sound of the fuel pump working when you unscrew the fuel tank cap, or you should feel pressure when pinching the fuel inlet hose with your hand;
(4) If the working sound of the fuel pump cannot be heard or there is no pressure in the inlet pipe, the fuel pump should be repaired or replaced;
(5) If there is a malfunction with the fuel pump not working and the above checks are normal, the fuel pump circuit wires, relays, and fuses should be checked for open circuits.
2. Check the resistance of the electric fuel pump
Measure the resistance (coil) of the two wiring terminals on the electric fuel pump using a multimeter resistance gauge. The resistance value should be 2-3 Ω (20-40 ℃). Otherwise, the electric fuel pump should be replaced.
3. Measurement of pressure and holding pressure of electric fuel pumps
The measurement method is: the battery voltage should be above 12Y, remove the negative cable of the battery, release the oil pressure of the fuel system, and connect the oil pressure gauge. After reconnecting the negative cable of the battery, use a jumper wire to short circuit the two detection holes of the electric fuel pump, then turn on the ignition switch, let the fuel pump work, and read the oil pressure on the oil pressure gauge. The value should meet the regulations. If it is higher than the specified value, the pressure regulator should be replaced; If it is lower than the specified value, check the fuel hose and connections for oil leakage, as well as check whether the fuel pump, gasoline filter, and gasoline pressure regulator are normal.
