Fuel Pressure And Residual Pressure, Checking, Vehicles With 3.2L FSI Engine
Special tools and workshop equipment required
- Injection Rate Comparison Meter Kit - Remote Cable VAG1348/3A with Injection Rate Kit - Remote Cable VAG1348/3-3.
- Connector Test Set VAG1594D
- Pressure Tester Kit VAS6550 with hose lines Pressure Tester Kit - Hose 1 VAS6550/1 and Pressure Tester Kit - Hose 2 VAS6550/2
- Measuring container, fuel-resistant
Procedure
-- Follow all test requirements, refer to TEST CONDITIONS .
-- Remove 1/3 of the rear seat, refer to REAR SEAT, REMOVING AND INSTALLING .
-- Remove the bolts -arrows- and remove the sealing flange cover -1-.
-- Disconnect the connector -1- on the sealing flange.
-- Push the circlip -1- upward in direction of -arrow A- and squeeze the release in direction of -arrow B-.
-- Press on the marked location in direction of -arrow A- and remove the cover -2-.
-- Release the latch in direction of -arrow B- and open the cover -1-.
-- Connect the Injection Rate Comparison Meter Kit - Remote Cable VAG1348/3A using the Injection Rate Kit - Remote Cable VAG1348/3-3 and cable from the Connector Test Set VAG1594D to the terminal -1-.
-- 2. Tape the Injection Rate Kit - Remote Cable VAG1348/3-3 with insulating tape -arrow-.
-- Connect the connector terminal -5- to the chassis ground with an adapter cable from the Connector Test Set VAG1594D.
-- Place the switch for the Injection Rate Comparison Meter Kit - Remote Cable VAG1348/3A toward front in engine compartment.
-- Connect the alligator clip to the Battery Jump Start Terminal -U6- -A- in the Terminal 30 Wire Junction 2 -TV22- in the plenum chamber.
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.
-- Loosen the clamp and remove the fuel line -1-.
-- Connect the Pressure Tester Kit - Hose 1 VAS6550/1 and adapter hose -1- to the fuel supply line and secure them with hose clamps -2-.
-- Connect the Pressure Tester Kit - Hose 1 VAS6550/1 to the Pressure Tester Kit VAS6550.
-- Connect the Pressure Tester Kit - Hose 2 VAS6550/2 and hold the hose in a fuel-resistant measuring container.
Risk of fuel leak.
- Make sure that the drain -C- is closed.
- The lever is perpendicular to the direction of flow.
-- Open the shut-off valves -A and B-.
- The levers point in the direction of flow.
-- Press the button of the remote control.
-- If the fuel flows without bubbles, close the drain -B-, so that the fuel pressure increases.
- The lever is perpendicular to the direction of flow.
-- Read the fuel pressure in the Pressure Tester Kit VAS6550:
- Specified value:5 to 6.5 bar (65 to 94 psi)
If the specification is not attained:
-- Fuel pump, checking fuel delivery quantity, refer to FUEL, CHECKING DELIVERY QUANTITY, VEHICLES WITH 3.2L FSI ENGINE .
Residual Pressure, Checking
-- Watch the pressure fall on the Pressure Tester Kit VAS6550 while checking the holding pressure and checking for leaks:
- After 10 minutes there must be a residual pressure of at least 3 bar (43 psi)
If the residual pressure drops below 3 bar (43 psi):
- Check the connection between the Pressure Tester Kit VAS6550 and the fuel supply line for leaks.
- Checking the Pressure Tester Kit VAS6550 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 FILTER, REMOVING AND INSTALLING .
-- Repeat the residual pressure check.
If there are still leaks:
- The fuel pump check valve in the fuel pump leaks: replace the fuel delivery unit, refer to FUEL DELIVERY UNIT/FUEL LEVEL SENSOR, REMOVING AND INSTALLING .
Assembly is performed in the reverse order of disassembly, noting the following:
- The ignition must be off.
Open the shut-off valve -B- and drain valve -C- and let the fuel drain into the measuring container before removing the pressure gauge for the fuel pressure.
-- Remove the Pressure Tester Kit VAS6550 with hose lines Pressure Tester Kit - Hose 1 VAS6550/1 and Pressure Tester Kit - Hose 2 VAS6550/2
-- Secure the fuel line with a clamp and then pull on it to make sure it is secure.