FSI Engines

FSI Engines

=> [ Transfer Fuel Pump, Left, Checking Electrical ]

=> [ Fuel Pump, Right, Checking Electrical ]

=> [ Fuel Delivery Pump, 8-Cylinder, Checking Delivery Quantity ]

=> [ Fuel Pump, Audi S8 10-Cylinder, Checking Fuel Delivery Rate ]

Transfer Fuel Pump, Left, Checking Electrical

• Fuel pump voltage supply on FSI engines is carried out at Fuel Pump (FP) Control Module (J538).

• Fuel Pump (FP) Control Module (J538) testing occurs in the VAS 5051/5052 "Guided Fault Finding" Function.

Fuel Pump, Right, Checking Electrical

• Fuel pump voltage supply on FSI engines is carried out at Fuel Pump (FP) Control Module (J538).

• Fuel Pump (FP) Control Module (J538) testing occurs in the VAS 5051/5052 "Guided Fault Finding" Function.

Fuel Delivery Pump, 8-Cylinder, Checking Delivery Quantity

Special tools, testers and auxiliary items required

• Pressure Gauge K-Jetronic (V.A.G 1318)

• Pressure Gauge Adapter (V.A.G 1318/10-12)

• Remote Control (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-3)

• Measuring container, fuel-resistant

Procedure

• Battery voltage min. 12.5 V.

• Is the Fuel Pump Control Module (J538) OK; check under "Guided Fault Finding" with Vehicle Diagnosis, Testing and Information System (VAS 5051B).

• Fuel filter OK.

• Fuel tank at least 1/4 filled.

• Ignition switched off.

Observe safety precautions. Refer to => [ Safety Precautions ] Fuel Supply System.

- Remove the cover of right luggage compartment side trim - arrows -.

- Remove cover - 2 - above battery.

• Ignore - 1 -.

- Remove the luggage compartment floor mat.

- Unbolt cover for left locking flange - arrows -.

- Disconnect electrical harness connector - 2 - at left locking flange.

• Ignore - 1 -.

- Unbolt cover for right locking flange - arrows -.

- Disconnect electrical harness connector - 2 - at right locking flange.

• Ignore - 1 -.

- Connect Remote Control for VAG 1348 (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-3) and adapter cables from Connector Test Set (V.A.G 1594C) to terminal - 4 - (ground) on left and right delivery unit.

- Route Remote Control (V.A.G 1348/3A) switch forward in engine compartment.

- Connect alligator clip to ground point in engine compartment.

- Connect terminal - 1 - (positive) on left and right delivery unit using a self-made adapter cable to vehicle battery "+". For safety reasons, install a fuse - A - (10 A) in the wiring.

- Remove fuel filler cap from fuel filler tube.

- Pull rear engine cover off - arrows -.

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

- Disconnect fuel supply line - arrow - on distribution piece.

Note rules of cleanliness for working on the fuel injection system. Refer to => [ Clean Working Conditions ] Fuel Supply System.

- Disconnect fuel line - arrow -.

- Connect Fuel Inj. Pressure Gauge-CIS (V.A.G 1318) with Adapter (V.A.G 1318/11) and (V.A.G 1318/12) in fuel line.

- Connect assisting hose - arrow - on pressure gauge and hold it in a measuring container.

- Open shut-off valve of pressure gauge set. The lever points in the direction of flow.

- Generate pressure in the fuel system by pressing the switch of the remote control and slowly closing the shut-off valve of the pressure gauge.

• Specified value: 4 bar positive pressure.

- From this point on do not move position of shut-off tap.

- Empty the measuring container.

- Press the switch on the remote control for 15 seconds.

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

• Voltage at fuel pump with engine stopped and pump running is approximately 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.

• Because the quantity of fuel delivered does not decrease significantly when one of the fuel pumps malfunctions - due to the internal lines in the tank - a faulty pump cannot be diagnosed accurately by measuring the quantity delivered.

In this case, proceed as follows:

- Remove electrical adapter cable at each fuel delivery unit.

- Measure the fuel delivery rate at opposite fuel delivery unit.

If the fuel delivery rate by the individually measured fuel delivery unit is considerably less than the specified value:

- Replace affected fuel delivery unit.

Assembly is in reverse order of removal, note the following:

- Attach fuel line to engine.

Fuel Pump, Audi S8 10-Cylinder, Checking Fuel Delivery Rate

Special tools, testers and auxiliary items required

• Pressure Gauge K-Jetronic (V.A.G 1318)

• Pressure Gauge Adapter (V.A.G 1318/10-12)

• Remote Control (V.A.G 1348/3A) with adapter cable (V.A.G 1348/3-3)

• Measuring container, fuel-resistant

Procedure

- Remove cover - 2 - above battery.

• Ignore - 1 -.

- Remove the luggage compartment floor mat.

- Unbolt cover for left locking flange - arrows -.

- Disconnect electrical harness connector - 2 - at left locking flange.

• Ignore - 1 -.

- Unbolt cover for right locking flange - arrows -.

- Disconnect electrical harness connector - 2 - at right locking flange.

• Ignore - 1 -.

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

Note rules of cleanliness for working on the fuel injection system => [ Clean Working Conditions ] Fuel Supply System.

- Disconnect fuel line - arrow - on fuel rail.

- Connect Fuel Inj. Pressure Gauge-CIS (V.A.G 1318) with Adapter (V.A.G 1318/11) and (V.A.G 1318/12) in fuel line.