Fuel Pressure and Residual Pressure Before High Pressure Pump, Checking
Fuel Pressure and Residual Pressure before High Pressure Pump, Checking
Special tools, testers and auxiliary items required
• Pressure Gauge K-Jetronic (V.A.G 1318)
• Adapter (V.A.G 1318/10)
• Adapter (V.A.G 1318/11)
• Remote Control (V.A.G 1348/3A) with adapter cable (V.A.G 1348/3-3)
• Connector Test Set (V.A.G 1594C)
• Measuring Container, Fuel-Resistant
• Protective Gloves
Fuel Pressure, Checking
• Battery voltage at least 12.5 V.
• Fuel filter OK.
• Fuel tank at least 1/4 filled.
• Fuel Pump (FP) Control Module (J538) OK.
• Ignition switched off.
- Remove right seat frame in 2nd row.
Wear protective gloves!
- Cut floor covering with a standard box cutter - 1 - along the perforation - arrows -.
- Fold carpet cut-out to side - arrow -.
- Remove nuts - 1 to 4 - and remove right locking flange cover - arrows -.
- Carefully release and disconnect electrical harness connector - arrow - at locking flange.
- Connect (V.A.G 1348/3A) with adapter cable (V.A.G 1348/3-3) and an adapter cable from (V.A.G 1594C) at terminal - 1 -.
- Cover 2nd connector terminal of adapter cable (V.A.G 1348/3-3) with insulating tape to prevent short circuit - arrow -.
- Connect terminal - 4 - with an adapter cable from (V.A.G 1594C) to chassis Ground (GND).
- Route remote control (V.A.G 1348/3 A) switch forward into engine compartment.
- Release retaining clip and open cover - A - over positive terminal pick-off in engine compartment.
- Connect the alligator clip to the positive terminal clamp.
- 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 - 3 - at distribution piece.
• Ignore - 1 - and - 2 -.
- Connect (V.A.G 1318) with adapters (V.A.G 1318/10) and (V.A.G 1318/11) in fuel line.
- Connect an assisting hose - arrow - to pressure gauge and hold it in a measuring container.
- Open shut-off valve of pressure gauge.
• The lever points in the direction of flow.
- Bleed the fuel system, by briefly pressing the remote control.
- Close shut-off valve of pressure gauge.
• Lever stands perpendicular to direction of flow - arrow -.
- Hold the switch of the remote control until no more pressure increase is observed on the fuel pressure gauge.
• Specified value: Approximately 6 bar positive pressure
If the specification is not obtained:
- Check the fuel pump delivery quantity.
Residual Pressure, Checking
- Check for leaks and for residual pressure by observing the pressure loss on the pressure gauge.
• After 10 minutes there must be a residual pressure of at least 3 bar.
If the residual pressure drops below 3 bar:
• Check connection between fuel pressure gauge and fuel line for leaks.
• Check pressure gauge for leaks.
• Check fuel lines and their connections for leaks.
• Replace fuel filter with integrated fuel pressure regulator.
• Replace fuel pump.
Assembly is in reverse order of removal, note the following:
• Before disconnecting pressure gauge, release pressure by opening shut-off valve. Hold a container in front of connection for this.
- Insert service tank access carpet frame in floor covering.
- Install right seat frame in 2nd row.