Cherokee, Grand Cherokee, 1999-2005

Fuel Rail (Supply Manifold) & Injectors

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Removal & Installation



2.5L & 4.0L Engines
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
    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.
  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).
  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.  

3.7L Engine
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
    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.
  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.  

4.7L Engine
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
  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. Remove wiring at rear of generator.
  14.  
  15. Disconnect fuel line latch clip and fuel line at fuel rail. A special tool will be necessary for fuel line disconnection.
  16.  
  17. Remove vacuum lines at throttle body.
  18.  
  19. Disconnect electrical connectors at all 8 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.
  20.  
  21. Disconnect electrical connectors at throttle body.
  22.  
  23. Disconnect electrical connectors at MAP and IAT sensors.
  24.  
  25. Remove first three ignition coils on each bank (cylinders #1, 3, 5, 2, 4 and 6).
  26.  
  27. Remove 4 fuel rail mounting bolts.
  28.  
  29. 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.
  30.  
  31. Remove fuel rail (with injectors attached) from engine.
  32.  
  33. If fuel injectors are to be removed, to Fuel Injector Removal/Installation.

    Click image to see an enlarged view

    Fig. Fuel rail-4.7L engines

  34.  

To install:

  1. Apply a small amount of engine oil to each fuel injector O-ring. This will help in fuel rail installation.
  2.  
  3. Position fuel rail/fuel injector assembly to machined injector openings in cylinder head.
  4.  
  5. Guide each injector into cylinder head. Be careful not to tear injector O-rings.
  6.  
  7. 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.
  8.  
  9. Install 4 fuel rail mounting bolts and tighten to 20 ft. lbs. (27 Nm).
  10.  
  11. Install ignition coils.
  12.  
  13. Connect electrical connectors to throttle body.
  14.  
  15. Connect electrical connectors to MAP and IAT sensors.
  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 vacuum lines to throttle body.
  20.  
  21. Connect fuel line latch clip and fuel line to fuel rail.
  22.  
  23. Connect wiring to rear of generator.
  24.  
  25. Install air box to throttle body.
  26.  
  27. Install air duct to air box.
  28.  
  29. Connect battery cable to battery.
  30.  
  31. Start engine and check for leaks.
  32.  

5.7L Engine
  1. Before servicing the vehicle, please familiarize yourself with safety procedures.
    CAUTION
    the fuel system is under constant pressure even with engine off. Before servicing fuel rail, fuel system pressure must be released.


    WARNING
    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.

  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 flex tube (air cleaner housing to engine).
  10.  
  11. Remove air resonator box at throttle body.
  12.  
  13. Disconnect all spark plug cables from all spark plugs and ignition coils. Do not remove cables from cable routing tray. Note original cable positions while removing.
  14.  
  15. Remove spark plug cable tray from engine by releasing 4 retaining clips. Remove tray and cables from engine as an assembly.
  16.  
  17. Disconnect electrical connectors at all 8 ignition coils.
  18.  
  19. Disconnect fuel line latch clip and fuel line at fuel rail. A special tool will be necessary for fuel line disconnection.

    Click image to see an enlarged view

    Fig. Quick-disconnect fittings

  20.  
  21. Disconnect electrical connectors at all 8 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.
  22.  
  23. Disconnect electrical connectors at all throttle body sensors.
  24.  
  25. Remove four fuel rail mounting bolts and hold-down clamps.
  26.  
  27. Gently rock and pull left side of fuel rail until fuel injectors just start to clear machined holes in intake manifold. Gently rock and pull right side of rail until injectors just start to clear intake manifold head holes. Repeat this procedure (left/right) until all injectors have cleared machined holes.
  28.  
  29. Remove fuel rail (with injectors attached) from engine.
  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 intake manifold. Be careful not to tear injector O-rings.
  8.  
  9. Push right side of fuel rail down until fuel injectors have bottomed on shoulders. Push left fuel rail down until injectors have bottomed on shoulders.
  10.  
  11. Install 4 fuel rail hold-down clamps and 4 mounting bolts. Torque to 100 inch lbs. (11 Nm).
  12.  
  13. Position spark plug cable tray and cable assembly to intake manifold. Snap 4 cable tray retaining clips into intake manifold.
  14.  
  15. Install all cables to spark plugs and ignition coils.
  16.  
  17. Connect electrical connector to throttle body.
  18.  
  19. Install electrical connectors to all 8 ignition coils.
  20.  
  21. Connect electrical connector to throttle body.
  22.  
  23. 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.
  24.  
  25. Connect fuel line latch clip and fuel line to fuel rail.
  26.  
  27. Install air resonator to throttle body (2 bolts).
  28.  
  29. Install flexible air duct to air box.
  30.  
  31. Connect battery cable to battery.
  32.  
  33. Start engine and check for leaks.
  34.  

 
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