Fuel Pump Delivery Quantity, Checking

Fuel Pump Delivery Quantity, Checking

Special tools, testers and auxiliary items required

• Hand held remote control (jumper).

• Multimeter.

• Electrical connector test lead set.

• Fuel pressure test set (high pressure).

• Measuring container, fuel-resistant.

Test conditions

• Fuse (S228) (position 28) OK

• Fuel Pump (FP) Relay (J17) OK.

• Battery voltage 12.5 V

• Fuel filter OK

• Fuel tank at least 1/4 filled.

• Fuel pressure regulator OK.

• Ignition switched off.

Test sequence

CAUTION!
Wear protective gloves!

- Remove right locking flange cover - arrows -.





- Disconnect the electrical harness connector - 1 - from the fuel delivery unit.





- Connect a Hand held remote control (jumper) to terminal - 1 - of the fuel delivery unit and to vehicle battery (+).

- Connect a jumper cable from an Electrical connector test lead set to terminal - 4 - of the fuel delivery unit and to vehicle Ground (GND).





- Remove the fuel filler cap from fuel filler tube.

- Remove rear engine cover - arrows -.





CAUTION!
Fuel system is under pressure! Before opening the system, place rags around the connection area. Then release the pressure by carefully loosening the connection.

- Disconnect fuel line - arrow - at distribution piece.





- Connect an assisting hose onto the disconnected fuel supply line and hold into a measuring container.





- Press switch on remote control for 15 seconds.

- Compare quantity of fuel delivered with minimum delivery rate in the diagram (cm3/15s).





• Voltage at the fuel pump with engine stopped and fuel pump running is approx. 2 volts less than battery voltage.

If minimum delivery quantity is not obtained, the following malfunctions may be present:

• Fuel lines pinched.

• Fuel filter clogged.

• Fuel pump faulty.

Assembly is performed in reverse order of removal.