Volkswagen Cars 2000-05

Fuel Injectors

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Removal & Installation





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Fig. Inner view of a mechanical fuel injector



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Fig. Pull the fuel injector wiring harness from the injector



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Fig. Observe the location of the injector wiring harness spring clips



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Fig. Close up of injector wiring harness



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Fig. Notice the arch in the injector wiring harness connector. It will only slide over the injector in one direction

  1. Relieve the fuel system pressure.
  2.  
  3. On CIS-E Motronic systems pull the injectors straight out of the intake manifold using a tool designed specifically for the job. Fuel injector removal tools are sold at most automotive suppliers or at your local VW dealer.
  4.  


NOTE
Use a spray lubricant to ease the removal of any stuck injectors.

  1. Now hold the fitting with a line wrench and unscrew the injector.
  2.  


NOTE
If it is difficult to remove the injectors from their lines, use a penetrant to aid in the process.

  1. The injectors can now be removed from the lines if desired.
  2.  

To install:

  1. Install the fuel injectors on the lines.
  2.  
  3. Lubricate the injector O-rings with a spray lubricant or gasoline.
  4.  
  5. Install the injectors.
  6.  



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Fig. Fuel injectors and fuel rail-1.8L Golf, GTI and Jetta shown: other models similar



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Fig. Fuel injectors and fuel rail-2.8L Golf, GTI and Jetta shown: other models similar

  1. Before servicing the vehicle, refer to the Precautions section.
  2.  
  3. Relieve the fuel system pressure.
  4.  
  5. Remove or disconnect the following:

    Negative battery cable
     
    Engine appearance cover, if equipped
     
    Engine under cover, if equipped
     
    Air cleaner and ducting
     
    All necessary vacuum and electrical connectors that interfere with fuel rail removal
     
    Fuel pressure and return lines
     
    Fuel injector connectors
     
    Fuel supply rail with injectors attached
     
    Fuel injectors from the supply rail
     

  6.  

To install:

  1. Install or connect the following:

    Fuel injectors to the fuel supply rail using new O-rings
     
    Fuel supply rail with injectors attached. Tighten the bolts to 89 inch lbs. (10 Nm)
     
    Fuel injector connectors
     
    Fuel pressure and return lines
     
    All necessary vacuum and electrical connectors
     
    Air cleaner and ducting
     
    Negative battery cable
     
    Engine appearance cover, if equipped
     
    Engine under cover, if equipped
     
    Negative battery cable
     

  2.  
  3. Start the engine, check for leaks and repair if necessary.
  4.  

  1. Relieve the fuel system pressure.
  2.  
  3. Remove the fuel pipe by unscrewing the union nuts.
  4.  
  5. Remove the fuel pipes at the pump and at the injectors.
  6.  
  7. Remove the fuel injection lines as an assembly.
  8.  
  9. Unscrew the injector from the cylinder head.
  10.  

To install:


NOTE
Replace the heat shields at each injector hole every time a new injector is installed.

  1. Screw the new injector into the cylinder head and tighten it.
  2.  
  3. Install the fuel line assembly.
  4.  

1.8L, 2.0L
  1. Turn the ignition switch OFF and remove the keys
  2.  
  3. Release the fuel system pressure. See 'Relieving Fuel System Pressure'
  4.  
  5. Remove or disconnect the following:
  6.  


    Fuel lines from the fuel injector rail
     
    Fuel rail bolts
     
    Fuel rail, with injectors
     


To install

  1. Installation is the reverse order of the removal procedure. Note the following:
  2.  
    1. Always replace the gasket (below the lower insert) before the fuel injectors are installed.
    2.  
    3. Before the upper insert is installed, clean the threads and apply a light coat of thread-lock compound.
    4.  


6-Cylinder Engines
  1. Remove the engine cover
  2.  
  3. Remove the air intake hose between the mass airflow sensor and intake air elbow
  4.  
  5. Remove all harness connectors to injectors
  6.  
  7. Disconnect vacuum hose from fuel pressure regulator
  8.  
  9. Expose wires at fuel rail
  10.  



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Fig. Removing the fuel injector rail

  1. Unscrew fuel rail from intake manifold (arrows)
  2.  


WARNING
Fuel system is under pressure! Place a cloth around the connection point before opening the system. Then release pressure by carefully loosening connection.

  1. Disengage retaining clip and remove the injector
  2.  

To install

  1. Installation is in reverse order of removal, noting the following:
  2.  
    1. Remove the O-rings from all opened connections. NEVER remove the plastic cap from valve head to replace front O-ring; pry the O-ring off over the plastic cap.
    2.  
    3. Lightly lubricate the O-ring with clean engine oil.
    4.  
    5. Make sure all the injectors are in place and seated correctly.
    6.  
    7. Check the clip to ensure an unobstructed fitting on injector.
    8.  
    9. Place the fuel rail with injectors into the intake manifold, and apply uniform pressure to press it in.
    10.  


Testing





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Fig. To test the injectors probe the two prongs at the rear of each injector with the leads of a multimeter . . .



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Fig. . . . set the meter to the ohms scale and check the resistance of each injector. A shorted injector will show zero ohms

  1. Unplug the connector at the end of the fuel rail.
  2.  
  3. Connect a Digital Volt Ohm Meter (DVOM) to the terminals and measure the resistance
  4.  
  5. If the resistance is high, remove the wiring from each injector and recheck each individually.
  6.  
  7. The resistance should be between 14-18 ohms.
  8.  
  9. If the injectors are not within specification, replace them with new ones.
  10.  

1.8L, 2.0L, 2.8L (V6 & Vr6)
Fuel Injector Electrical Diagnosis And Activation

WARNING
Fire hazard! Do NOT smoke or work near heaters or open flame. Do NOT have anything nearby that could ignite fuel. The fuel system is under pressure. Before opening, cover connections with a rag, and open carefully to release pressure.

  1. Obtain the following special tools and equipment:
  2.  


    VAG 1551 or VAG 1552 scan tool, with VAG 1551/3 adapter cable
     
    Audi A4, VW 1594 test kit
     
    VAG 1598/22 test box
     
    Multimeter US1119 (Fluke 83, or equivalent)
     
    VAG 1348/3A remote control, with adapter cable VAG1348/32
     
    VAG 1527B LED voltage tester
     
    VAG 1602 measuring glass from calibration tester
     
    Wiring diagram for the specific vehicle and engine being tested
     

  3. Verify that the engine speed sensor and fuel pump are operational.
  4.  
  5. Remove all components necessary for access to the fuel injectors.
  6.  
  7. Using the scan tool, run the 'Diagnostic Test' mode for actuating the fuel injectors.
  8.  
  9. If one or more injectors Do NOT click, perform the following tests:
  10.  
    1. Disconnect the 5-pin harness connector from ignition coil.
    2.  
    3. Disconnect the harness connectors (1) from all injectors (2).
    4.  
    5. Connect the VAG 1527B LED voltage connector terminals for cylinder/fuel injector, using the adapter cables from VW1594 connector test kit.
    6.  
    7. Operate the starter and check voltage supply for cylinder No. 1 fuel injector.
    8.  
    9. The LED must flicker.
    10.  
    11. Repeat the test for all remaining injectors.
    12.  
    13. Turn the ignition switch off.
    14.  
    15. Connect the VAG1527B LED voltage tester to cylinder No. 1 harness connector terminal No. 1 and ground.
    16.  
    17. Operate the starter.
    18.  
    19. The LED must light.
    20.  
    21. If the LED does not light, switch the ignition OFF and check the wire between the 2-pin connector terminal No. 1 and the fuel pump relay for an open circuit. The specified value is 1.5 ohms (maximum).
    22.  
    23. Connect the VAG 1598/22 test box to ECM harness connector.
    24.  
    25. Check the wiring for open circuits between the ECM/test box and each fuel injector.
    26.  
    27. Check the wiring for short circuits between all circuit wires and connector terminals.
    28.  
    29. Check the wiring between connector terminal No. 1 of all injectors and ground for open circuit.
    30.  




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Fig. Disconnecting the harness from all injectors



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Fig. Checking for a proper ground, using VAG 1527B tester



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Fig. Connecting the test box VAG1598/22 to the ECM harness

  1. To check for fuel injector resistance perform the following:
  2.  
    1. Remove the harness connector from each injector.
    2.  
    3. With a DVOM, check the resistance at each fuel injector. Specified resistance is 13.5-15.5 ohms.
    4.  
    5. If the injector is not within specification, replace the injector.
    6.  


Fuel Injector Leak Test

NOTE
Verify proper operation of the fuel pressure regulator prior to performing these tests.

  1. Remove all components necessary in order to remove the fuel rail and attached injectors.
  2.  
  3. Remove the injector rail and injectors as an assembly. Support this assembly out of the way above the manifold.
  4.  


NOTE
Leave the injector harness attached to injectors.

  1. Conduct an output Diagnostic Test Mode (DTM), actuating the No. 1 cylinder fuel injector. The fuel pump must be running.
  2.  


NOTE
This step allows the fuel pump to run without the engine running. The closed throttle position switch must be closed during the test, or the selected injector will be activated 5 times, discharging fuel.

  1. Visually check fuel injector for leaks. A maximum of 1 to 2 drops per minute per injector.
  2.  
  3. If leak exceeds allowed amount, switch the ignition key OFF and replace the injector.
  4.  


NOTE
Always replace the seals.

 
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