Fuel Pressure and Residual Pressure, Checking, S5 Through MY 2011

Fuel Pressure and Residual Pressure, Checking, S5 through MY 2011

Special tools, testers and auxiliary items required

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

• Adapter (V.A.G 1318/10-12) and Adapter (V.A.G 1318/15)

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

• Measuring container, fuel-resistant

Procedure






- Follow all test requirements. Refer to => [ Test Conditions ] Initial Inspection and Diagnostic Overview.

- Remove the rear bench seat.

- Remove the locking flange cover - arrows -.

- Disconnect the connector - 1 - on the locking flange.






- Connect the (V.A.G 1348/3A) using the (V.A.G 1348/3-3) and cable from the (V.A.G 1594C) to the terminal - 1 -.






- Tape (V.A.G 1348/3-3) with insulating tape - arrow - to prevent a short circuit.

- Connect the connector terminal - 5 - to the chassis Ground (GND) with an adapter cable from the (V.A.G 1594C).

- Route (V.A.G 1348/3A) toward the front in the engine compartment.

- Remove the center plenum chamber cover.






- Release the retainer - arrow A - and open the cover - arrow B -.






- Connect the alligator clip to the battery jump start terminal (U6) - A - in the terminal 30 wire junction 2 (TV22) in the plenum chamber.






- Open the fuel filler door.






- Remove the fuel filler cap - arrow -.

- Remove the engine cover - arrows -.













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 the fuel line - arrow -.

- Connect the (V.A.G 1318) with the (V.A.G 1318/11) and (V.A.G 1318/12) in the fuel line.






- Push an assisting hose - arrow - onto it and hold it into a measuring container.

- Open the shut-off valve on the pressure gauge.

• The lever points in the direction of flow.

- Press the switch for the remote control and slowly close the shut-off valve for the pressure gauge.

- If the fuel flows without bubbles, close the drain, so that the fuel pressure increases.

• The level is perpendicular to the direction of flow.

- Read the fuel pressure on the (V.A.G 1318) :

• Specified value: 5.0 to 8.0 bar (72 to 116 psi).

If the specification is not attained:

- Check the fuel delivery quantity for the fuel pump. Refer to => [ Fuel Delivery Rate, Checking, S5 through MY 2011 ] .

Checking Holding Pressure

- Check for leaks and constant pressure. Watch the (V.A.G 1318) for a drop in pressure while doing this:

• After 10 minutes there must be a residual pressure of at least 3 bar.

If the holding pressure drops below 3 bar:

• Check the connections between the (V.A.G 1318) and the fuel supply line for leaks.

• Check the (V.A.G 1318) for leaks.

• Check fuel lines and their connections for leaks.

If no faults are detected:

• Replace the locking flange with the fuel filter and fuel pressure regulator. Refer to => [ Fuel Delivery ] Fuel Delivery.

- Repeat the residual pressure check.

If there are still leaks:

• There is a leak at the check valve in the fuel pump: Replace the fuel delivery unit => [ Fuel Delivery ] Fuel Delivery.

Assemble in reverse order of disassembling. Note the following:

• The ignition must be off.

• Decrease the fuel pressure by opening the drain and letting the fuel run into the measuring container before removing the pressure gauge.






- Remove the (V.A.G 1318) and the hose lines.

- Attach the fuel line so that it clicks into place.

- Press the fuel line on again and pull to make sure the connection is engaged correctly.