GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Century (China) 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Fuel Injector Replacement

Removal Procedure

Notice: Use care in removing the fuel injectors in order to prevent damage to the fuel injector electrical connector pins or the fuel injector nozzles. Do not immerse the fuel injector in any type of cleaner. The fuel injector is an electrical component and may be damaged by this cleaning method.

Important: 

   • The fuel injector o-rings can be serviced seperate from the fuel injectors.
   • If the fuel injectors are found to be leaking, inspect the engine oil for fuel contamination.


    Object Number: 12687 Size: SH
  1. Relieve fuel system pressure. Refer to Fuel Pressure Relief .
  2. Remove the upper intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical.
  3. Remove the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement .
  4. Remove the fuel injector retaining clips (2).
  5. Remove the fuel injectors (3).
  6. Remove the fuel injector Upper O-ring (1).
  7. Remove the fuel injector lower O-ring (5).
  8. Remove the fuel injector lower O-ring Backup (4).

Installation Procedure

Important: Important each fuel injector is calibrated for a specific flow rate. Be sure to use the correct part number when ordering replacement fuel injectors. When replacing the fuel injector O-rings, be sure to install the brown O-ring in the lower position. The fuel injector lower O-ring uses a nylon collar, called the O-ring backup, to properly position the O-ring on the fuel injector. Be sure to Install the O-ring backup, or the sealing O-ring may move on the fuel injector when installing the fuel rail. If the sealing O-ring is not seated properly, a vacuum leak is possible and driveability complaints may occur.


    Object Number: 12687 Size: SH
  1. Install the fuel injector Upper O-ring (1).
  2. Install the fuel injector lower O-ring Backup (4).
  3. Install the fuel injector lower O-ring (5).
  4. Install the fuel injector (3) to fuel rail.
  5. Install the fuel injector retaining clips (2).
  6. Install the fuel rail. Refer to Fuel Injection Fuel Rail Assembly Replacement .
  7. Install the upper intake manifold. Refer to Intake Manifold Replacement in Engine Mechanical .
  8. Tighten the fuel filler cap.
  9. Reconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  10. Inspect for fuel leaks using the following procedure:
    11. 10.1. Turn ON the ignition, for 2 seconds.
    10.2. Turn OFF the ignition, for 10 seconds.
    10.3. Turn ON the ignition.
    10.4. Inspect for fuel leaks.