Liberty, Wrangler 2006-2007

Fuel Rail (Supply Manifold) & Injectors

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Removal & Installation



2.4L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
    CAUTION
    the fuel system is under constant pressure even with engine off. Before servicing fuel rail, fuel system pressure must be released.

  2.  

The fuel rail can be removed without removing the intake manifold if the following procedures are followed.

Click image to see an enlarged view

Fig. Fuel rail-2.4L engines

  1. Remove fuel tank filler tube cap.
  2.  
  3. Perform Fuel System Pressure Release Procedure.
  4.  
  5. Remove negative battery cable at battery.
  6.  
  7. Remove air duct at throttle body.
  8.  
  9. Disconnect fuel line latch clip and fuel line at fuel rail. A special tool will be necessary for fuel line disconnection.
  10.  
  11. Remove necessary vacuum lines at throttle body.
  12.  
  13. Drain engine coolant and remove thermostat and thermostat housing.
  14.  
  15. Remove PCV hose and valve at valve cover.
  16.  
  17. Remove 3 upper intake manifold mounting bolts, but only loosen 2 lower bolts about 2 turns.
  18.  
  19. Disconnect 2 main engine harness connectors at rear of intake manifold.
  20.  
  21. Disconnect 2 injection wiring harness clips at harness mounting bracket.
  22.  
  23. Disconnect electrical connectors at all 4 fuel injectors. Push red colored slider away from injector. While pushing slider, depress tab and remove connector from injector. The factory fuel injection wiring harness is numerically tagged (INJ 1, INJ 2, etc.) for injector position identification. If harness is not tagged, note wiring location before removal.
  24.  
  25. Remove 2 injection rail mounting bolts.
  26.  
  27. Gently rock and pull fuel rail until fuel injectors just start to clear machined holes in intake manifold.
  28.  
  29. Remove fuel rail (with injectors attached) from intake manifold. Remove the injector clips, then remove the injectors from the rail.

    Click image to see an enlarged view

    Fig. Fuel pressure regulator-2.4L engines

  30.  

To install:

  1. Clean out fuel injector machined bores in intake manifold.
  2.  
  3. Apply a small amount of engine oil to each fuel injector O-ring. This will help in fuel rail installation.
  4.  
  5. Position fuel rail/fuel injector assembly to machined injector openings in intake manifold.
  6.  
  7. Guide each injector into cylinder head. Be careful not to tear injector O-rings.
  8.  
  9. Push fuel rail down until fuel injectors have bottomed on shoulders.
  10.  
  11. Install 2 fuel rail mounting bolts and tighten to 250 inch lbs. (28 Nm).
  12.  
  13. Connect electrical connectors at all fuel injectors. Push connector onto injector and then push and lock red colored slider. Verify connector is locked to injector by lightly tugging on connector.
  14.  
  15. Snap 2 injection wiring harness clips into brackets.
  16.  
  17. Connect 2 main engine harness connectors at rear of intake manifold.
  18.  
  19. Tighten 5 intake manifold mounting bolts.
  20.  
  21. Install PCV valve and hose.
  22.  
  23. Install thermostat and radiator hose. Fill with coolant.
  24.  
  25. Connect necessary vacuum lines to throttle body.
  26.  
  27. Connect fuel line latch clip and fuel line to fuel rail.
  28.  
  29. Install air duct to throttle body.
  30.  
  31. Connect battery cable to battery.
  32.  
  33. Start engine and check for leaks.
  34.  

3.7L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
    CAUTION
    the fuel system is under constant pressure even with engine off. Before servicing fuel rail, fuel system pressure must be released.


    NOTE
    The left and right fuel rails are replaced as an assembly. Do not attempt to separate rail halves at connector tube. Due to design of tube, it does not use any clamps. Never attempt to install a clamping device of any kind to tube. When removing fuel rail assembly for any reason, be careful not to bend or kink tube.



    Click image to see an enlarged view

    Fig. Fuel rail-3.7L engines

  2.  
  3. Remove fuel tank filler tube cap.
  4.  
  5. Perform Fuel System Pressure Release Procedure.
  6.  
  7. Remove negative battery cable at battery.
  8.  
  9. Remove air duct at throttle body air box.
  10.  
  11. Remove air box at throttle body.
  12.  
  13. Disconnect fuel line latch clip and fuel line at fuel rail. A special tool will be necessary for fuel line disconnection.
  14.  
  15. Remove necessary vacuum lines at throttle body.
  16.  
  17. Disconnect electrical connectors at all 6 fuel injectors. Push red colored slider away from injector. While pushing slider, depress tab and remove connector from injector. The factory fuel injection wiring harness is numerically tagged (INJ 1, INJ 2, etc.) for injector position identification. If harness is not tagged, note wiring location before removal.
  18.  
  19. Disconnect electrical connectors at throttle body sensors.
  20.  
  21. Remove 6 ignition coils.
  22.  
  23. Remove 4 fuel rail mounting bolts.
  24.  
  25. Gently rock and pull left side of fuel rail until fuel injectors just start to clear machined holes in cylinder head. Gently rock and pull right side of rail until injectors just start to clear cylinder head holes. Repeat this procedure (left/right) until all injectors have cleared cylinder head holes.
  26.  
  27. Remove fuel rail (with injectors attached) from engine. Remove the injector clips, then remove the injectors from the rail.
  28.  

To install:

  1. Clean out fuel injector machined bores in intake manifold.
  2.  
  3. Apply a small amount of engine oil to each fuel injector O-ring. This will help in fuel rail installation.
  4.  
  5. Position fuel rail/fuel injector assembly to machined injector openings in cylinder head.
  6.  
  7. Guide each injector into cylinder head. Be careful not to tear injector O-rings.
  8.  
  9. Push right side of fuel rail down until fuel injectors have bottomed on cylinder head shoulder. Push left fuel rail down until injectors have bottomed on cylinder head shoulder.
  10.  
  11. Install 4 fuel rail mounting bolts and tighten to 100 inch lbs. (11 Nm)
  12.  
  13. Install 6 ignition coils.
  14.  
  15. Connect electrical connectors to throttle body.
  16.  
  17. Connect electrical connectors at all fuel injectors. Push connector onto injector and then push and lock red colored slider. Verify connector is locked to injector by lightly tugging on connector.
  18.  
  19. Connect necessary vacuum lines to throttle body.
  20.  
  21. Connect fuel line latch clip and fuel line to fuel rail.
  22.  
  23. Install air box to throttle body.
  24.  
  25. Install air duct to air box.
  26.  
  27. Connect battery cable to battery.
  28.  
  29. Start engine and check for leaks.
  30.  

4.0L Engine
  1. Before servicing the vehicle, refer to the Precautions section.
    CAUTION
    The fuel system is under constant fuel pressure even with engine off. This pressure must be released before servicing fuel rail.


    NOTE
    The fuel damper is not serviced separately



    Click image to see an enlarged view

    Fig. Fuel rail-4.0L engines

  2.  
  3. Remove fuel tank filler tube cap.
  4.  
  5. Perform Fuel System Pressure Release Procedure.
  6.  
  7. Disconnect negative battery cable from battery.
  8.  
  9. Remove air tube at top of throttle body.
    NOTE
    Some engine/vehicles may require removal of air cleaner ducts at throttle body.

  10.  
  11. Disconnect electrical connectors at all 6 fuel injectors. Push red colored slider away from injector. While pushing slider, depress tab and remove connector from injector. The factory fuel injection wiring harness is numerically tagged (INJ 1, INJ 2, etc.) for injector position identification. If harness is not tagged, note wiring location before removal.
  12.  
  13. Disconnect fuel supply line latch clip and fuel line at fuel rail.
  14.  
  15. Disconnect throttle cable at throttle body.
  16.  
  17. Disconnect speed control cable at throttle body (if equipped).
  18.  
  19. Disconnect automatic transmission cable at throttle body (if equipped).
  20.  
  21. Remove cable routing bracket at intake manifold.
  22.  
  23. If equipped, remove wiring harnesses at injection rail studs by removing nuts.
  24.  
  25. Clean dirt/debris from each fuel injector at intake manifold.
  26.  
  27. Remove fuel rail mounting nuts/bolts.
  28.  
  29. Remove fuel rail by gently rocking until all the fuel injectors are out of intake manifold. Remove the injector clips, then remove the injectors from the rail.
  30.  

To install:

  1. Clean each injector bore at intake manifold.
  2.  
  3. Apply a small amount of clean engine oil to each injector O-ring. This will aid in installation.
  4.  
  5. Position tips of all fuel injectors into the corresponding injector bore in intake manifold. Seat injectors into manifold.
  6.  
  7. Install and tighten fuel rail mounting bolts to 100 + / - 25 inch lbs. (11 + / - 3 Nm) torque.
  8.  
  9. If equipped, connect wiring harnesses to injection rail studs.
  10.  
  11. Connect electrical connectors at all fuel injectors. Push connector onto injector and then push and lock red colored slider. Verify connector is locked to injector by lightly tugging on connector.
  12.  
  13. Connect fuel line and fuel line latch clip to fuel rail.
  14.  
  15. Install protective cap to pressure test port fitting (if equipped).
  16.  
  17. Install cable routing bracket to intake manifold.
  18.  
  19. Connect throttle cable at throttle body.
  20.  
  21. Connect speed control cable at throttle body (if equipped).
  22.  
  23. Connect automatic transmission cable at throttle body (if equipped).
  24.  
  25. Install air tube (or duct) at top of throttle body.
  26.  
  27. Install fuel tank cap.
  28.  
  29. Connect negative battery cable to battery.
  30.  
  31. Start engine and check for fuel leaks.
  32.  

 
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