MPI Engines

MPI Engines

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

=> [ Fuel Pump, Right, Checking Electrical ]

=> [ Fuel Pumps, Checking Fuel Delivery Rate, Vehicles with Fuel Return Line ]

=> [ Fuel Pumps, Checking Delivery Rate, Vehicles without Fuel Return Line ]

Transfer Fuel Pump, Left, Checking Electrical

Special tools, testers and auxiliary items required

• Remote Control Connection (V.A.G 1348/3A)

• Hand-Held Multimeter (V.A.G 1526D)

• Connector Test Set (V.A.G 1594C)

• Vehicle Diagnosis, Testing and Information System (VAS 5051B) with Inductive Pickup (100A) (VAS 5051B/7)

Procedure

Vehicles of MY 2003:

• Fuse 10 on fuse panel SF10 (in relay and fuse panel in right of luggage compartment) OK

Vehicles from MY 2004:

• Fuse 2 on fuse panel SF2 (in relay and fuse panel in right of luggage compartment) OK

All Vehicles

• Fuel Pump (FP) 2 Relay (J49) OK (on the relay and fuse panel in right of luggage compartment, Socket 3).

• Battery voltage min. 12.5 V

• Fuel filter OK.

• Ignition switched off.

Checking voltage supply

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

Vehicles of MY 2003:

- Pull out fuse 10 on fuse panel SF10 (in relay and fuse panel in right of luggage compartment, Socket 10).

Vehicles from MY 2004:

- Pull out fuse 2 on fuse panel SF2 (in relay and fuse panel in right of luggage compartment, Socket 2).

All Vehicles

- Connect Remote Control (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-2) to the right socket terminal of removed fuse.

- Connect alligator clip on Remote Control (V.A.G 1348/3A) to battery "+".

- Press the switch on the remote control.

• Operating noise of the pump must be audible in vicinity of fuel tank.

• Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump. If necessary, use a second technician to check.

If no operating noise can be heard:

- Remove the luggage compartment floor mat.

- Unbolt cover for left locking flange - arrows -.

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

• Ignore - 1 -.

- Connect multimeter between terminal - 1 - and - 4 - of electrical harness connector for voltage measurement.

- Press the switch on the remote control.

• Specified value: approximately battery voltage.

If the specification is not obtained:

- Repair the wiring harness according to the wiring diagram.

If specified value is obtained, although no running-noise can be heard at pump:

- Remove left fuel delivery unit. Refer to => [ Left Fuel Delivery Unit with Transfer Fuel Pump ] MPI Engines.

- Check if the electrical wiring between the flange and fuel pump is connected and has continuity.

If no fault is detected in the wiring:

- Fuel pump faulty. Replace left fuel delivery unit.

- Install left fuel delivery unit. Refer to => [ Left Fuel Delivery Unit with Transfer Fuel Pump ] MPI Engines.

Current Draw, Checking

• Fuel pump voltage supply OK

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

- Connect alligator clip on Remote Control (V.A.G 1348/3A) to battery "+".

- Connect Vehicle Diagnosis, Testing and Information System (VAS 5051B) with 100A inductive pickup (VAS 5051B/7) to wire of remote control.

- Press the switch on the remote control.

- Measure current draw of fuel pump.

• Specified value: approximately 8 A

If the specification is not obtained:

• At a displayed current draw of 4 A, Fuel Pump (FP) runs dry.

Fuel Pump, Right, Checking Electrical

Special tools, testers and auxiliary items required

• Remote Control Connection (V.A.G 1348/3A)

• Hand-Held Multimeter (V.A.G 1526D)

• Connector Test Set (V.A.G 1594C)

• Vehicle Diagnosis, Testing and Information System (VAS 5051B) with Inductive Pickup (100A) (VAS 5051B/7)

Procedure

• Battery voltage min. 12.5 V

• Fuse - 31 - on fuse holder SC31 (right side instrument panel) OK

• Fuel Pump Relay (J17) OK (on the relay and fuse panel in right front footwell), Socket - 4 -.

• Fuel filter OK.

• Ignition switched off.

Checking voltage supply

- Pry off the right cover on the instrument panel, using a screwdriver - arrow -.

- Pull out fuse 31 on fuse panel SC31 (right instrument panel, middle row, first large fuse from top).

- Connect Remote Control (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-2) to the left socket terminal of fuse SC31.

- Connect alligator clip on Remote Control (V.A.G 1348/3A) to battery "+".

- Press the switch on the remote control.

• Operating noise of the pump must be audible in vicinity of fuel tank.

• Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump. If necessary, use a second technician to check.

If no operating noise can be heard:

- Remove the luggage compartment floor mat.

- Unbolt cover for right locking flange - arrows -.

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

• Ignore - 1 -.

- Connect multimeter between terminal - 1 - and - 4 - of electrical harness connector for voltage measurement.

- Remove right fuel delivery unit. Refer to => [ Right Fuel Delivery Unit with Fuel Pump ] MPI Engines.

- Check if the electrical wiring between the flange and fuel pump is connected and has continuity.

If no fault is detected in the wiring:

- Fuel pump faulty. Replace right fuel delivery unit.

- Install right fuel delivery unit. Refer to => [ Right Fuel Delivery Unit with Fuel Pump and Fuel Gauge Assembly Overview ] MPI Engines Overview.

Current Draw, Checking

• Fuel pump voltage supply OK

- Pull out fuse 31 on fuse panel SC31 (right instrument panel, middle row, first large fuse from top).

- Connect Remote Control (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-2) to the left socket terminal of fuse SC31.

Fuel Pumps, Checking Fuel Delivery Rate, Vehicles with Fuel Return Line

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.

• Fuel Pump Relay (J17) OK (on the relay and fuse panel in right front footwell), Socket - 4 -.

• Fuel Pump (FP) 2 Relay (J49) OK (on the relay and fuse panel in right of luggage compartment, Socket 3).

• 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.

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. Refer to => [ Clean Working Conditions ] Fuel Supply System.

- Disconnect fuel supply line - 2 - at fuel rail.

• Ignore - 1 -.

- 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, noting the following:

- Attach fuel supply line to fuel rail.

Fuel Pumps, Checking Delivery Rate, Vehicles without Fuel Return Line

Special tools, testers and auxiliary items required

• Adapter (V.A.G 1318/26)

• 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.

• Fuel Pump Relay (J17) OK (on the relay and fuse panel in right front footwell), Socket - 4 -.

• Fuel Pump (FP) 2 Relay (J49) OK (on the relay and fuse panel in right of luggage compartment, Socket 3).

- 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. Refer to => [ Clean Working Conditions ] Fuel Supply System.

- Disconnect fuel return line - 1 - from locking flange by pressing release buttons.

• Ignore - 2 -.

- Connect Adapter (V.A.G 1318/26) to disconnected fuel line - 1 - and hold it in a measuring container.

- 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.

- Connect alligator clip to ground point near battery.

- 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.

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