Fuel Injector


  • Often an individual injector needs to be replaced.
  • Random dissassembly of the components and improper procedures can result in damage to one of the various systems located near the injectors.
  • The injectors are normally attached directly to a fuel rail and inserted into the intake manifold or cylinder head.
  • They must be positively sealed because high pressure fuel leaks can cause a serious safety hazard.
  • Prior to loosening any fitting in the fuel system, the fuel pump fuse should be removed.
  • As an extra precaution, disconnect the negative cable at the battery.
  • To remove an injector, the fuel rail must be able to move away from the engine.
  • The rail-holding brackets should be unbolted and the vacuum line to the pressure regulator disconnected.
  • Disconnect the wiring harness to the injectors by depressing the center of the attaching wire clip.
  • The injectors are held to the fuel rail by a clip that fits over the top of the injector.
  • O-rings at the top and at the bottom of the injector seal the injector.
  • Pull up on the fuel rail assembly.
  • The bottoms of the injectors will pull our of the manifold while the tops are secured to the rail by clips.
  • Remove the clip from the top of the injector and remove the injector unit.
  • Install new O-rings onto the new injector.
    • Be careful not to damage the seals while installing them, and make sure they are in their proper locations.
  • Lightly lubricate the sealing ring with engine oil or automatic transmission fluid (avoid using silicone grease, which tends to clog the injectors) to prevent seal distortion or damage.
  • Install the injector into the fuel rail and set the rail assembly into place.
  • Tighten the fuel rail hold-down bolts according to manufacturer's specifications.
Art courtesy of Delmar - Thomson Learning.
  • Reconnect all parts that were disconnected.
  • Install the fuel pump fuse and reconnect the battery.
  • Turn the ignition switch to the run position and check the entire system for leaks.
  • After a visual inspection has been completed, conduct a fuel pressure test on the system.