audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
Checking fuel pressure regulating valveN276 > < Installing high-pressure pipes

A3 Mk2

Checking pressure retention valve in fuel return line
Checking pressure retention valve in fuel return line
The pressure retention valve maintains a residual pressure of approx. 10 bar in the fuel return line.
This residual pressure is required for the control function of the injectors
Special tools and workshop equipment required
   
t  Tester for fuel return system -VAS 6330-
  WARNING
t  Always read rules for cleanliness and instructions for working on fuel system → Chapter.
t  Follow these instructions and rules for cleanliness before starting work and while working on the fuel system.
–  Remove engine cover panel → Chapter.
–  Remove noise insulation from injectors.
–  Clean return line connection on cylinder 1 (with commercial cleaning solution or similar) before removing.
–  Dry return line connection on cylinder 1.
–  Cover return line connection on cylinder 1 with a cloth.
  W00-10775
–  Pull return line connection off cylinder 1; to do so, press both tabs down and at the same time pull release pin upwards -arrow-.
  Note
No dirt must be allowed to get into the disconnected return line or the open connection on the injector.
  N15-10404
–  Connect tester for fuel return system -VAS 6330- between return line connection on injector and return line.
–  Start engine.
–  Check pressure indicated on tester.
l  Specification: approx. 10 bar
If the value does not match the specification, fit a new pressure retention valve.
  Note
The pressure retention valve may only be renewed together with the fuel return lines.
  A23-10115

Checking fuel pressure regulating valveN276 > < Installing high-pressure pipes