Fuel Delivery Rate, Checking, A5 From MY 2012, A4 From MY 2013

Fuel Delivery Rate, Checking, A5 from MY 2012, A4 from MY 2013

Special tools, testers and auxiliary items required

• Pressure tester (VAS 6550) with hoses (VAS 6550/1) and (VAS 6550/2)






• Vehicle tester

• Measuring container, fuel-resistant

Procedure






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

- Open the fuel filler door.

- Remove the fuel filler cap - arrow -.








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.

- Pull the release ring - 1 - and disconnect the fuel line - 2 -,

- Connect the pressure tester (VAS 6550) and hose line (VAS 6550/2) to the fuel supply line.






- Connect the hose line (VAS 6550/1) and hold it inside a fuel resistant container.








Risk of fuel leak.

• Make sure that the drain - C - is closed.

• The level is perpendicular to the direction of flow.

- Open the drains - A - and - B -.

• The levers point in the direction of flow.

- Connect the tester.

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

• OBD

• Engine Electronics

• Basic Setting

• Empty Fuel Tank

• In order to measure the fuel delivery rate, there must be an initial pressure inside the fuel line against which the fuel pump must work during the measuring. Adjust the initial pressure using pressure tester (VAS 6550) as follows:

- Press Start and create an initial pressure in the fuel system: the fuel pump starts to run and slowly close the shut-off valve - B - on the pressure tester.






• Specified value: 4.3 bar positive pressure.

- From this point on do not move position of shut-off valve.

- Press the Stop button.

- Empty measuring container.

- To measure, press the Start button again and let the fuel pump run for 15 seconds.

- After 15 seconds, press the Stop button.

- Check the amount of fuel in the measuring container.

• Specified value: Minimum delivery rate 800 cm3/15 s.

If minimum delivery quantity is not obtained, the following malfunctions may be present:

• The fuel lines are pinched.

• The fuel filter is clogged.

• The fuel pump is faulty.

Assemble in reverse order of disassembling. Note the following:

- Remove the pressure tester (VAS 6550) with hoses (VAS 6550/1) and (VAS 6550/2).

- 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.