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Fuel Injector Cleaning Procedure

WARNING: This page is about a different car, the 2004 GMC Sierra and 2004 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

  1. Loosen the fuel fill cap to relieve vapor pressure in the fuel tank.
  2. Remove the positive crankcase ventilation (PCV) clean air tube from air inlet duct and set aside.
  3. Remove the resonator and air inlet duct from throttle body.
  4. Remove the brake booster vacuum hose and connector from intake manifold.
  5. Remove the electrical connector from the central sequential fuel injection (CSFI) fuel metering body.
  6. Remove the spark plug wires from 1, 3 and 5 from the distributor cap.
  7. Remove the fuel line bolt (4) at the rear of intake manifold.
    8. Fig 1: Fuel Pipe & Components
    GM334517Courtesy of GENERAL MOTORS CORP.
  8. Relieve the fuel system pressure.
  9. Remove the nuts (1) and clamp (2) from the fuel pipe.
    10. Fig 2: View Of Fuel Pipe Nuts & Clamps
    GM648217Courtesy of GENERAL MOTORS CORP.
  10. Remove fuel pipes from the metering body.
    11. IMPORTANT: Make sure that the fuel pipe O-rings, washers, and spacers are present and in their proper position.
  11. Install the J 44466-12  (2) and the J 44466-13  (1) to the metering body and tighten.
    12. Fig 3: View Of J 44466-12 & J 44466-13
    GM648221Courtesy of GENERAL MOTORS CORP.
  12. Install the J 44466-11  (4), clamp (2) and J 44466-13  (1) to the fuel pipe and tighten.
    13. Fig 4: View Of J 44466-11, Clamp, J 44466-13 & Fuel Pipe
    GM648219Courtesy of GENERAL MOTORS CORP.
  13. Obtain the J 41413  , close the valve (2) on the tank (3), and remove the regulator assembly.
  14. Install the J 44466-10  (5) to the J 41413  tank (3)
    15. Fig 5: View Of J 44466-10, J 41413 & Tank
    GM648216Courtesy of GENERAL MOTORS CORP.
  15. Connect the J 44466-10  hose (1) to the J 44466-12  (3).
  16. Install the J 39021  , the J 39021-210  and J 39021-301  (4) to the metering body electrical connector.
    17. Fig 6: View Of J 44466-10, J 44466-12, J 39021, J 39021-210 & J 39021-301
    GM648224Courtesy of GENERAL MOTORS CORP.
  17. Adjust the amperage selector switch on J 39021  to 0.5 amps.
  18. Open the valve (2) on the tank (3).
  19. Open the valve (4) on the J 44466-10  to pressurize the fuel system. Then close valve (4) before firing injectors.
    IMPORTANT: The minimum pressure required on the gage (6) is 150 psi. If 150 psi is not obtained, the tank (3) must be refilled prior to performing this procedure.
  20. Fire one injector using the J 39021  . Observe a pressure drop on the gage (6) and verify the injector/poppet valve operation. An injector/poppet that is stuck and not operational will have no pressure drop on the gage. If an injector remains stuck, repeat the procedure multiple times (as required) until the injector is operational.
  21. Repeat steps 19 and 20 for each individual injector to verify that all injector/poppet valve assemblies are unstuck and functional.
  22. Shut off the pressure valve (2) on the tank (3) of the J 41413  .
    23. Fig 7: View Of J 44466-10, J 41413 & Tank
    GM648216Courtesy of GENERAL MOTORS CORP.
  23. Bleed off the pressure at the J 44466-10  .
  24. Install the PCV fresh air tube to the air inlet duct.
  25. Disconnect and remove the J 44466-10  (1) from the J 44466-12  (3) and the J 41413  .
    26. Fig 8: View Of J 44466-10, J 44466-12, J 39021, J 39021-210 & J 39021-301
    GM648224Courtesy of GENERAL MOTORS CORP.
  26. Remove the J 39021-301  , J 39021-210  and J 39021  from the metering body.
  27. Install the vehicle electrical connector to the metering body.
  28. Install brake booster vacuum hose and connector to the intake manifold.
  29. Install ignition wires 1, 3, and 5 to the distributor cap.
  30. Install the resonator and air intake duct to the throttle body and hand tighten wing nut.
  31. Obtain J 38500-A  (2).
    IMPORTANT: Make sure the valve at the bottom of the canister (3) is closed.
    32. Fig 9: Identifying Fuel Injector Cleaner
    GM651337Courtesy of GENERAL MOTORS CORP.
  32. Remove the canister top and add top engine cleaner GM P/N 1050002 (Canadian P/N 992872) to the canister.
  33. Fill the remainder of the canister with regular unleaded gasoline and install the canister top.
  34. Suspend J 38500-A  from a convenient underhood location.
  35. Connect the hose from J 38500-A  (1) to the service port on the J 44466-12  (3).
    36. Fig 10: View Of J 44466-10, J 44466-12, J 39021, J 39021-210 & J 39021-301 Attached To Throttle Body
    GM648224Courtesy of GENERAL MOTORS CORP.
  36. Open valve (3) at the bottom of J 38500-A  .
  37. Connect a shop air source to the fitting at the top of J 38500-A  and adjust the regulator (1) to 75 psi.
    38. Fig 11: Identifying Fuel Injector Cleaner
    GM651337Courtesy of GENERAL MOTORS CORP.
  38. Let the vehicle run at idle until the canister is empty and the vehicle stalls.
  39. Remove the shop air supply from J 38500-A  .
  40. Depressurize the J 38500-A  .
  41. Disconnect the J 38500-A  hose from the J 44466-12  .
  42. Remove the PCV clean air tube from the air inlet duct and set aside.
  43. Remove the resonator and air inlet duct from the throttle body and set aside.
  44. Remove ignition wires 1, 3, and 5 from the distributor cap.
  45. Remove brake booster vacuum hose and connector from the intake manifold.
  46. Bleed the residual pressure from J 44466-12  .
  47. Remove J 44466-13  (1) and J 44466-12  (2) from the metering body.
    48. Fig 12: View Of J 44466-12 & J 44466-13
    GM648221Courtesy of GENERAL MOTORS CORP.
  48. Remove J 44466-13  (1), clamp (2) and J 44466-11  (4) from the fuel pipe (3).
    49. Fig 13: View Of J 44466-11, Clamp, J 44466-13 & Fuel Pipe
    GM648219Courtesy of GENERAL MOTORS CORP.
    IMPORTANT: Make sure that all of the O-rings (6 and 8), washers (7), and spacers (5) are present and in proper position.
  49. Install the fuel pipe (3) to the metering body.
    50. NOTE: Refer to Fastener Notice in Cautions and Notices.
  50. Install the clamp (2) and nuts (1).

    Tighten:  Tighten the nuts to 3 N.m (27 lb ft).

  51. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489), or equivalent to the threads of the fuel pipe bolt (4).
    52. Fig 14: Fuel Pipe & Components
    GM334517Courtesy of GENERAL MOTORS CORP.
  52. Install the fuel pipe bolt.

    Tighten:  Tighten the bolt to 6 N.m (53 lb ft).

  53. Install the brake booster vacuum hose and connector to the intake manifold.
  54. Install the resonator and air inlet duct to the throttle body.
  55. Install the PCV clean air tube to the inlet duct.
  56. Install brake booster vacuum hose and connector to the intake manifold.
  57. Install ignition wires 1, 3, and 5 to the distributor cap.
  58. Add 1 ounce of port fuel injector cleaner GM P/N 12345104 (Canadian P/N 12345515), or equivalent to the vehicle fuel tank for each gallon of gasoline estimated to be in the tank.
    IMPORTANT: Instruct the customer to add the remainder of the bottle of port fuel injector cleaner to the vehicle fuel tank at the next fill up.
  59. Hand tighten the fuel tank filler cap.
  60. Start the vehicle and check for fuel leaks.
  61. Using a Tech II scan tool, check for any stored Powertrain DTC codes. Clear codes as required.
  62. Disconnect Tech II scan tool.
    IMPORTANT: Advise the customer to change brands of fuel.
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