Malfunctions of the electric fuel pump

The power supply voltage for the electric fuel pump is supplied via a relay. The pump pumps in fuel from the engine start stage and delivers it all the time the engine is running. The second safety relay is activated when the engine is stopped with the ignition on (the control unit does not receive crankshaft speed signals) and interrupts the current supply to the engine control unit. This is necessary so that gasoline cannot leak out during an accident. The fuel pump must be checked by a workshop. If there is a suspicion of a malfunction in the fuel pump of the car, you should limit yourself to the following troubleshooting.



SEQUENCE OF WORK

1. Disconnect the ignition.

2. Disconnect the fuel pressure line from the fuel distribution line, while keeping a rag ready to collect the escaping fuel.

3. Even with the engine off, some gasoline should leak out, as the fuel system is under pressure.

4. If the pipe is dry, briefly turn on the ignition without including the starter.

5. If the fuel pump does not start, check the fuse or safety relay.

6. If gasoline still does not flow, check the fuel pump relay.


7. The fuel pump should start working.

8. Otherwise, remove the upholstery under the rear seat and tap the pump housing with light blows of a hammer - sometimes this helps.

9. Check up reliability of connection of an electric socket of the fuel pump.

10. If the fuel pump still does not work, turn on the ignition and check the voltage with an LED tester (the control lamp can damage the control unit).

11. If there is voltage, then the pump is faulty or the wire is broken.



Pic. 10.6. Electric roller rotary fuel pump: 1 - suction side; 2 - safety valve; 3 - filter housing; 4 - rotor; 5 - check valve; 6 - pressure side

12. If the pump works, but the fuel does not flow through the pressure fuel line - the fuel filter or fuel line is clogged, or the fuel line is pinched (pic. 10.6).

13. If, despite all efforts, the pump does not work, it remains only to replace it, since the chance to repair the pump is very unlikely.