With Manufacturer's Scan Tool

Fuel Injectors, Checking For Leaks And Quantity Injected

Special tools, test equipment and auxiliary items






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

Test conditions
- Check that the fuel pressure is in order, Checking fuel pressure regulator and holding pressure. Fuel Pressure Regulator and Residual/Holding Pressure, Checking

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

Test sequence






- Disconnect connectors from fuel injectors.
- Remove fuel rail complete.
- Disconnect vacuum hose from fuel pressure regulator.
- Lift fuel rail with fuel injectors off intake manifold and support it.

Checking for leaks
- Initiate output Diagnostic Test Mode (DTM) (fuel pump must run). [1][2]Output Diagnostic Test Mode (DTM) (Function 03)


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


- Check fuel 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.
- Replace malfunctioning fuel injector, item 10.

Pay attention to the following when installing the fuel injector:
- Replace O-rings on all fuel injectors and lightly moisten with clean engine oil.
- Insert fuel injectors vertically and in the correct position into the fuel rail and secure with retaining clips.
- Install fuel rail with secured fuel injectors onto intake manifold and press in evenly.
- The connectors must audibly engage in the fuel injectors when pushed on.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes

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







- Connect one terminal of fuel injector to be tested to engine Ground (GND) using auxiliary cables from VAG 1594.
- Connect second fuel injector terminal with auxiliary cable to VAG 1348/3 remote control using VAG 1348/3-2 adapter cable.
- Connect alligator clip to battery (+).
- Initiate output DTM (fuel pump must run). [1][2]Output Diagnostic Test Mode (DTM) (Function 03)


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


- Operate VAG 1348/3 remote control for 30 seconds.
- Repeat check on other fuel injectors. Use new measuring glasses.
- After all fuel injectors have been activated, place measuring glasses on a horizontal surface and compare injected quantity.

Specification: 133 to 157 ml per injector

If the measuring values of one or more fuel injectors are above or below the prescribed specifications:
- Switch off ignition.
- Replace malfunctioning fuel injector, item 10.

Pay attention to the following when installing the fuel injector:
- Replace O-rings on all fuel injectors and lightly moisten with clean engine oil.
- Insert fuel injectors vertically and in the correct position into the fuel rail and secure with retaining clips.
- Install fuel rail with secured fuel injectors onto intake manifold and press in evenly.
- Check DTC Memory, if necessary, repair any malfunctions and then Erase DTC Memory, Checking and Erasing DTC Memory. Reading Diagnostic Trouble Codes
- Read readiness code. If DTC memory has been erased or Motronic Engine Control Module (ECM) -J220- was disconnected from battery positive, readiness code must be generated again.
Monitors, Trips, Drive Cycles and Readiness Codes
Monitors, Trips, Drive Cycles and Readiness Codes