Fuel Injectors, Checking For Injection Quantity and Proper Seal

Injectors, Checking For Leaks And Quantity Injected (Engine Codes AVH, BBW)







Special tools and equipment
- V.A.G 1348/3 Remote control
- V.A.G 1348/3-2 Adapter
- V.A.G 1602 Calibration tester
- V.A.G 1594 A Adapter set
- V.A.G 1598/31 Test box

Requirements
- Fuel pressure must be OK. Testing and Inspection

WARNING: The fuel system is under pressure. Before opening the system remove fuse 28 and place a cloth around the connection. Then release the pressure by carefully loosening the connection.

Work sequence
- Remove wiper arms and cowl panel:







- Connect test box V.A.G 1598/31 to control module wiring harness. Engine control module remains disconnected.
- Remove intake manifold upper part.
- Disconnect connector from all injectors.

Engines: AVH, AZG
- Remove vacuum hose from fuel pressure regulator

Continued for all engines
- Remove securing bolts on fuel rail.
- Pull hose off air line for air shrouded injectors.
- Lift fuel rail along with injectors off intake manifold and support.
- Bridge test box sockets 1 and 65 using adapter cable from adapter set V.A.G 1594.

NOTE: This work sequence allows the fuel pump to run when the engine is not running.

- Switch ignition on.

Checking for leaks
- Check injector for leaks (visual check).

Only 1 to 2 drops per minute must emit from each injector when fuel pump is running

If fuel loss is greater:
- Switch ignition off and replace leaky injector.
- Erase DTC memory to return learned values to a neutral (default) position, Interrogating and erasing DTC memory

NOTE: Always replace O-rings and moisten them with engine clean oil.

Checking quantity injected

Requirements
- Test box V.A.G 1598/31 still connected and test box sockets 1 and 65 are still bridged using adapter cables from adapter set V.A.G 1594.
- Insert injector to be checked in a measuring glass of calibration tester V.A.G 1602.







- Connect one contact of injector to be tested to engine Ground using adapter cables from V.A.G 1594.
- Using adapter cables connect second injector contact to remote control V.A.G 1348/3 with adapter cable V.A.G 1348/3-2.
- Connect alligator clip to battery positive (+).
- Switch ignition on. Fuel pump must run.
- Operate remote control V.A.G 1348/3 for 30 seconds.
- Repeat check on other injectors. Use another (clean and dry) measuring beaker for each.
- After all injectors have been activated, place measuring glasses on a horizontal surface and compare quantity injected.

Specification: 85 to 105 ml per injector


If the measured values of one or more injectors are above or below the prescribed specifications:
- Replace faulty injector
- Erase DTC memory to return learned values to a neutral (default) position, Interrogating and erasing DTC memory. With Manufacturer's Scan Tool

Perform installation of injectors in reverse order. Note the following:
- Replace O-rings on all injectors and moisten then lightly with clean engine oil.
- Insert injectors vertically and in the correct position into the fuel rail and secure with retaining clips.
- Set fuel rail with secured injectors on intake manifold and press in evenly.