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
• Pry Lever - Rmv Outside Mirror (80 - 200)
• Fuel Inj. Pressure Gauge-CIS (V.A.G 1318)
• Adapter (V.A.G 1318/11)
• Adapter (V.A.G 1318/12)
• Remote Control (V.A.G 1348/3A) with Adapter Cable (V.A.G 1348/3-3)
• Measuring container, fuel-resistant
Test Conditions
• Battery voltage min. 12.5 Volts.
• Fuel filter OK.
• Fuel tank at least 1/4 filled.
• Fuel pump control module (J538) OK; for checking.
Fuel Pressure, Checking
• Ignition switched off.
- Install the protective body covers. Refer to => [ Protective Body Covers, Installing ] Procedures.
- Move the seat all the way forward.
- Move the seat backrest all the way forward.
CAUTION!
Risk of destroying electrical components when battery is disconnected.
• Follow the instructions when disconnecting the battery.
• Only disconnect battery with ignition switched off.
- Slide the battery cover in the direction of the - arrow a - and remove - arrow b -.
- With the ignition switched off, disconnect the battery ground (GND) cable - arrow -.
- Remove the rear shelf.
- Remove the right rear relay and fuse carrier from the control module bracket and lay it aside.
- Remove the right rear connector station from the control module bracket and lay it aside.
- Disconnect the control module electrical connectors and remove the control module bracket - 1 - from the vehicle.
- Press the harness - 2 - off the base of the rear bulkhead using the (80 - 200) - arrows - and free it up.
- Fold the insulation mats - 1 - on the right side of the vehicle to the side.
• The illustration shows the left side of the vehicle.
- Remove the bolts - 1 - through - 4 - and the right locking flange cover.
• The locking flange cover is sealed with adhesive sealant.
- Disconnect the electrical connector on the right locking flange - arrow -.
• Ignore - 1, 2 and 3 -.
- Connect the (V.A.G 1348/3A) with (V.A.G 1348/3-3) with an adapter cable from the connector test set (V.A.G 1594C) at terminal - 1 -.
- Using insulating tape, tape over the second terminal on the (V.A.G 1348/3-3) - arrow - to prevent a short circuit.
- Connect terminal - 5 - with an adapter cable from (V.A.G 1594C) to chassis Ground (GND).
- Connect the alligator clip to battery positive.
- Remove fuel filler cap from fuel filler tube.
R8 Coupe
- Remove the left engine compartment trim - 1 -.
R8 Spyder
- Remove the left engine compartment trim panel - 1 -.
Continuation for All Vehicles
CAUTION!
The fuel system is under low pressure. Wear protective eyewear and protective clothing to prevent injuries and contact with skin. Before opening the fuel system, place a cloth around the connection. Then reduce residual pressure by carefully removing connection.
- Disconnect fuel supply line - 1 -.
• Ignore - 2 -.
- Connect (V.A.G 1318) with (V.A.G 1318/11) and (V.A.G 1318/12) in the fuel line.
- Connect assisting hose - arrow - on 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 -.
- Press the remote control switch until the (V.A.G 1318) now longer shows the pressure increasing.
• Specified value: Approximately 5.5 bar (4.5 to 6.5 bar) positive pressure.
If the specification is not obtained:
- Check the fuel pump delivery quantity.
Residual Pressure, Checking
- Check for leaks and residual pressure by watching for the pressure on the (V.A.G 1318) to decrease.
• After 10 minutes there must be a residual pressure of at least 3.0 bar.
If the residual pressure drops below 3.0 bar:
• Check the connection between the (V.A.G 1318) and fuel supply line for leaks.
• Check the (V.A.G 1318) 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 the hose in a measuring container - arrow -.
- Connect the fuel supply line - 1 -. Check for cleanliness and leaks.
- Install the engine compartment trim.
Tightening Specifications
