B - Pressure Test In The Fuel Supply Line

Fig 1: Identifying Shut-Off Valves A And B On Pressure Tester Kit

Courtesy of AUDI OF AMERICA, LLC

• Connect the measuring setup as if measuring the delivery quantity.
• Vehicle Diagnostic Tester still connected.

-- Turn the Pressure Tester Kit:VAS6550  -1- on by pressing the On/Off  button.

-- Open the shut-off valves -A and B-.

• The levers point in the direction of flow.

-- Press Start  on the Vehicle Diagnostic Tester display: The fuel pump starts running.

-- 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: 5.0 to 8.0 bar

-- Press the Stop  button.

If Specified Value Is Obtained, Although the Fuel Delivery Unit Is Not OK.

• Fuel filter in the locking flange is blocked or the fuel supply line is crushed.

If the Specification Is Not Attained:

• Fuel delivery unit or fuel pressure regulator (in the locking flange) is faulty.