Fuel Pump, Checking Pressure and Delivery

Fuel Pump, Checking Pressure and Delivery

If, while driving, irregularities in the engine appear at high RPM and

• No malfunctions are stored the engine control module DTC memory => [ Engine Control Module ] .

• If the tandem pump is OK => [ Tandem Pump, Checking ] Tandem Pump, Checking.

• The fuel filter replacement intervals are maintained

Check the fuel pump pressure and delivery.

Special tools, testers and auxiliary items required

• Union nut tool (3217 )

• pressure gauge (V.A.G 1318)

• Adapter (V.A.G 1318/1)

• Adapter (V.A.G 1318/11)

• Pressure gauge adapter (V.A.G 1318/17)

• Double connection (V.A.G 1318/23)

• Remote control connection (V.A.G 1348/3A)

• Connector test set (V.A.G 1594C)

Test Conditions

• Voltage supply OK.

• Battery voltage at least 12.5 V

• Fuel temperature 15 to 30 ° C

• Fuel conforming to DIN EN 590 - no bio-diesel

• Fuel tank minimum 1/4 full

Test Sequence

Observe safety precautions => [ Safety Precautions ] .

Observe rules for cleanliness => [ Clean Working Conditions ] .

Connect the Remote Control

- Fold rear seat bench forward.

- Remove cover from fuel delivery unit.

- Disconnect 4 pin connector on the fuel delivery unit.

- Disconnect the adapter cables (V.A.G 1594 C ) on the fuel pump contact - 1 - and battery (+).





- Connect the contacts - 4 - from the connector and fuel pump using an adapter cable from (V.A.G 1594 C ).

Check the Pressure and Delivery

- Disconnect the fuel supply line - 1 - from the fuel line on the strut tower and connect the pressure gauge ( V.A.G 1318) and the adapter (V.A.G 1318/23) and (V.A.G 1318/17-8) to the fuel supply line.





- Connect hose (V.A.G 1318/1) onto adapter (V.A.G 1318/11) of pressure gauge and hold it in a measuring container.

- Close the shut-off valve on the pressure gauge - Position A -.

- Operate the remote control (V.A.G 1348/3A) for approximately 5 seconds.

The gauge must show a pressure of 0.5 ± 0.1 bar.

If the pressure is not attained:

- Check the fuel line to the fuel delivery unit.

- If this is OK, replace the fuel delivery unit => [ Fuel Delivery Unit ] .

If the pressure is attained, check the quantity as follows:

- Open shut-off valve of pressure gauge.





Lever will point in direction of flow - B -.

- Operate remote control (V.A.G 1348/3A ). Slowly close shut-off tap, until pressure gauge shows 0.2 bar.

- Do not operate the remote control. Now do not change the position of the shut-off valve.

- Empty the measuring container and place it once again under the drain hose.

- Operate the remote control for 30 seconds and measure the quantity of fuel.

Specified value: minimum 666 ml/30 s

If the minimum delivery rate is not attained:

- Check the fuel line to the fuel delivery unit.

- If this is OK, replace the fuel delivery unit => [ Fuel Delivery Unit ] .