Fuel Pump Delivery Rate, Checking

Fuel Pump Delivery Rate, Checking

Special tools, testers and auxiliary items required

• Fuel Inj. Pressure Gauge-CIS (V.A.G 1318)

• Adapter (V.A.G 1318/11)

• Adapter (V.A.G 1318/17-1A)

• Fuel Line Feed Adapter (V.A.G 1318/23)

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

• Connector Test Set (V.A.G 1594C)

• Measuring container, fuel-resistant

Procedure

Observe test conditions, refer to => [ Test Conditions ] General Information.

TT Coupe:

- Remove rear seat bench.

TT Roadster:

- Remove the right side rear panel trim panel.

All Vehicles:

- Unclip the retainers - arrows - of the cover for sealing flange.






- Disconnect the connector - arrow - from the locking flange.






- Connect the (V.A.G 1348/3A) with (V.A.G 1348/3-3) with an adapter cable from (V.A.G 1594C) at terminal - 1 -.






- Cover the second connector terminal of (V.A.G 1348/3-3) with insulating tape to prevent short circuit - arrow -.

- Connect contact - 5 - to vehicle Ground (GND) using a jumper cable from the (V.A.G 1594C).

- Connect alligator clip to battery positive (positive terminal pick-off in engine compartment).

- Remove the fuel cap from the fuel filler tube.

Vehicles with Toothed Belt Drive:

- Disengage fuel line on bracket and remove heat shield - 1 - on fuel line separating point.






There is a risk of injury because the fuel is under high pressure.

• To reduce pressure in fuel system, lay a clean cloth around the connector and carefully loosen connector.

- Disconnect fuel line - arrow - by pulling release ring.

Vehicles with Timing Chain Drive:

- Disconnect the fuel line by first stretching the boot - 1 - downward.






- First push the hose coupling - 2 - downward - arrow A -, then press the release buttons - arrow B -.

- Remove the hose coupling with the release buttons pressed.

All Vehicles:

- Attach (V.A.G 1318/23) and (V.A.G 1318/17-1A) to (V.A.G 1318).






- Push (V.A.G 1318/17-1A) onto disconnected fuel line.

- Attach the (V.A.G 1318/11) to (V.A.G 1318).

- Push an assisting hose - arrow - onto it and hold it into 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 valve.

- 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.

Assemble in reverse order of disassembling. Note the following:

TT Roadster:

- Install the right side rear panel trim panel.

TT Coupe:

- Install rear seat bench.