Fuel Pump (FP) Delivery Quantity, Checking

Fuel Pump (FP) 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 (cu.cm/15s).

NOTE: 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.