audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

Fuel and Residual Pressure before High Pressure Pump, Checking|Page 8876 > < Fuel and Residual Pressure before High Pressure Pump, Checking|Page 8874
Page 5
background image

-

Hold switch of remote control until no more pressure increase is observed on fuel pressure gauge.

‹› Specified value: approximately 6 bar positive pressure

If specification is not obtained:

-

Check delivery quantity of Fuel Pump (FP) => Fuel Supply System 20 Diagnosis and Testing.

Checking Residual Pressure

-

Check for leaks and for residual pressure by observing the pressure loss on the pressure gauge.

‹› After 10 minutes there must be a residual pressure of at least 3.75 bar.

The holding pressure drops below 3.75 bar:

‹› Check connection between fuel pressure gauge and fuel line for leaks. 

‹› Check pressure gauge for leaks.

‹› Check fuel lines and their connections for leaks.

‹› Replace fuel filter with integrated fuel pressure regulator => Fuel Supply System 20 Removal and Installation.

‹› Replace fuel pump => Fuel Supply System 20 Removal and Installation.

Assembly is in reverse order of removal, note the following:

‹› Before disconnecting pressure gauge, release pressure by opening shut-off valve. Hold a container in front of connection for this.

Tightening Specifications

Fuel and Residual Pressure before High Pressure Pump, Checking|Page 8876 > < Fuel and Residual Pressure before High Pressure Pump, Checking|Page 8874