Fuel Pressure And Residual Pressure, Checking, Vehicles With 3.0L TFSI Engine

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Special tools and workshop equipment required

Pressure Tester Kit VAS6550 with hose lines Pressure Tester Kit - Hose 1 VAS6550/1 and Pressure Tester Kit - Hose 2 VAS6550/2
Vehicle Diagnostic Tester
Measuring container, fuel-resistant

Procedure

Fig 1: Identifying Version 2 Cylinder Bank 1 (Right)

Courtesy of AUDI OF AMERICA, LLC

-- Follow all test requirements, refer to TEST CONDITIONS .

WARNING:

Risk of injury from fuel.

To reduce fuel pressure, lay cloths around connecting point before opening fuel system and carefully loosen.

-- Press the release buttons and disconnect the fuel hose -1-.

NOTE:

Ignore the -arrows-.

-- Connect the Pressure Tester Kit VAS6550 with the Pressure Tester Kit - Hose 2 VAS6550/2 to the fuel supply line.

Fig 2: Holding Test Kit Adapter Hose Into Fuel-Resistant Measuring Container

Courtesy of AUDI OF AMERICA, LLC

-- Connect the Pressure Tester Kit - Hose 1 VAS6550/1 and hold the hose in a fuel-resistant measuring container.

Fig 3: Identifying Pressure Tester VAS 6550 And Shut-Off Valve -B- (Closed)

Courtesy of AUDI OF AMERICA, LLC

CAUTION:

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.

-- Connect the Vehicle Diagnostic Tester.

-- Turn on the ignition and select the following menu items on the Vehicle Diagnostic Tester:

OBD
Engine Electronics
Basic Setting
Empty Fuel Tank

-- Push Start : the fuel pump starts.

-- 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: 4 to 8 bar (58 to 116 psi)

-- Press the Stop button.

If the specification is not attained:

-- Fuel pump, checking fuel delivery quantity, refer to FUEL, CHECKING DELIVERY QUANTITY, VEHICLES WITH 3.0L TFSI 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.

NOTE:

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.

Fig 4: Identifying Pressure Tester VAS 6550 And Shut-Off Valve -B- (Closed)

Courtesy of AUDI OF AMERICA, LLC

-- Remove the Pressure Tester Kit VAS6550 with hose lines Pressure Tester Kit - Hose 1 VAS6550/1 and Pressure Tester Kit - Hose 2 VAS6550/2

-- 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.