Fuel Injectors For Leaks and Quanity Injected, Checking

Special tools and equipment







- VAG 1348/3 Remote control
- VAG 1348/3-2 Adapter
- VAG 1602 Calibration tester

Test conditions
- The fuel pressure must be in order; check. Testing and Inspection


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


Test sequence
- Pull connectors off injectors.
- Then remove fuel rail complete.
- Pull off vacuum hose from fuel pressure regulator.
- Lift fuel rail with injectors off intake manifold and support it.

Checking for leaks
- Initiate Output Diagnostic Test Mode; the fuel pump must run. Refer to "Scan Tool Testing/Output Diagnostic Test Mode (DTM) Initiating" Testing and Inspection


NOTE:
- This step serves only to run the fuel pump when the engine is stopped.
- During the Output Diagnostic Test Mode, the injectors are activated. Before initiate the Output Diagnostic Test Mode, you must disconnect the injector connectors.
- Check injector for leaks (visual check). Only 1 to 2 drops per minute must emit from each valve when fuel pump is running.


If the fuel loss is greater:
- Switch off ignition and replace leaking injector.


NOTE: Always replace seals.


Checking injected quantity
- Insert injector to be checked in a measuring glass of tester for injected quantity VAG 1602.







- Connect one contact of the injector to be tested to engine Ground using auxiliary cables from VAG 1594.
- Connect the second injector contact with auxiliary cable to remote control VAG 1348/3 using adapter cable VAG 1348/3-2.
- Connect crocodile clip to battery ( + ).
- Initiate Output Diagnostic Test Mode; the fuel pump must run. Refer to "Scan Tool Testing/Output Diagnostic Test Mode (DTM) Initiating" Testing and Inspection


NOTE:
- This step serves only to run the fuel pump when the engine is stopped.
- During the Output Diagnostic Test Mode, the injectors are activated. Before initiate the Output Diagnostic Test Mode, you must disconnect the injector connectors.


- Operate remote control VAG 1348/3 for 30 seconds.
- Repeat check on the other injectors. To do this use new measuring beakers.
- After all injectors have been activated, place the measuring glasses on a horizontal surface and compare the injected quantity.
Specification: 133 - 157 ml per injector


NOTE: If the measured values of one or more injectors are above or below the prescribed specifications:


- Replace defective injector.

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