Remove fuel pump relay from relay panel. Install Jumper Switch (US 4480/3). Attach Fuel Quantity Analyzer (US 4480) to bumper and secure in place. See Fig 1 . Remove injectors from cylinder head with fuel lines attached. Check and replace fuel injector "O" rings if necessary.
Check tightness of injector inserts (2-piece inserts). If inserts are loose, remove and clean threads. Use sealing compound when installing upper insert. Place sealing washer against cylinder head, below lower portion of insert. Lubricate injector "O" rings with gasoline. Install injectors with fuel lines connected into fuel quantity analyzer tubes.
Ensure lines are not kinked or bent. Loosen fittings to align fuel lines and retighten. Remove rubber boot from airflow sensor housing above sensor plate. Turn and lift setting screw and adjusting slide of Sensor Plate Adjustable Holder (VW 1348/1) into upper position. See Fig 2 . This simulates full throttle operation.

Fig 1: Identifying Fuel Quantity Analyzer (US 4480) Components
Courtesy of AUDI OF AMERICA, INC.

Chapter Navigation

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Injector Quantity Comparison (2.2L)