Fuel Pump (FP) Delivery Quantity, Checking
WARNING: This page is about a different variant/trim than selected.
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 → General Diagnosis
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 seconds.
- 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