Fuel Delivery, Checking
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
Special tools, testers and auxiliary items required
- Hand held remote control (jumper).
- Multimeter.
- Electrical connector test lead set.
- Measuring container, fuel-resistant.
Test conditions
- Battery voltage 12.5 V
- Fuel filter OK
- Fuel tank at least 1 /4 filled.
- Fuel pressure regulator OK.
- Ignition switched off.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to → Preliminary Check
Start diagnosis
- Open cover from fuse box at left side of instrument cluster.
- Remove fuse 28 at fuse holder.
- Connect remote control connection at right terminal of socket of fuse S28.
- Connect alligator clip to vehicle battery B+.
- Remove the fuel filler cap from fuel filler.
CAUTION:
Fuel system is under pressure! Before opening the system, place rags around the connection area. Then release the pressure by carefully loosening the connection.
- Remove the bolt - 1 - and the cover above reservoir - arrow -.
Fig 2: Disconnecting Fuel Return Line From Line Tube & Connecting VAG1318/17 Adapter To Fuel Return Line From Engine
- Disconnect the fuel return line - 1 - from the line connection - 2 - by pressing the release button.
- Connect the Fuel pressure test set (high pressure) onto the disconnected fuel return line.
- Press switch on remote control for 15 Sec.
- Compare quantity of fuel delivered with minimum delivery rate in the diagram (cm 3 /15s).
NOTE:
- Voltage at the fuel pump with engine stopped and fuel pump running is approx. 2 volts less than battery voltage.
If minimum delivery quantity is not obtained, the following malfunctions may be present:
- Fuel lines pinched.
- Fuel filter clogged.
- Fuel pump faulty.
Assembly is performed in reverse order of removal.
End of procedure