How to Replace a CFI Fuel Injector

Fuel injectors are subject to wear and tear. As they approach the end of their service life, the engine gets harder to start, idles erratically and hesitates as you step on the accelerator. Fortunately, a central fuel injection (CFI) unit is not difficult to replace if done with care. Although designs and exact replacement procedures vary from one manufacturer to another, but you can replace the fuel injector in the throttle body of your engine.

Things You'll Need

• 2 combination wrenches or ratchet
• Flat-head screwdriver
• Phillips screwdriver
• Slip-joint pliers
• Engine oil

Instructions

1. Open the hood of your vehicle and disconnect the cable from the negative terminal of the battery using a pair of combination wrenches or ratchet.

2. Relieve the fuel system pressure.

3. Remove the air cleaner assembly from the top of the engine to leave the throttle body injector exposed.

4. Disconnect the wire connector leading to the fuel injector, being careful no to damage or break the locking tabs.

5. Remove the fuel meter surrounding the fuel injector if the particular throttle body on your engine is equipped with this unit. Use a standard screwdriver and unscrew the meter, making sure to leave the screws in their respective holes in the unit, as some of them may be of different length.

6. Unscrew and remove the retainer holding the injector in place. You might need a Phillips screwdriver to remove both screws.

7. Pull the injector from its seat using slip-joint pliers. If you need to, use a screwdriver to disengage the injector from its seat, being careful no to damage the throttle body unit.

8. Pull out both O-rings from inside the injector housing once you remove the injector.

9. Install new O-rings on the new fuel injector and apply a light coat of engine oil around the O-rings. Make sure the rings and any required washers are properly installed on the injector unit.

10. Install the injector on its bore by hand and make sure it is sitting properly. Reinstall the retainer, fuel meter, electrical connector, air cleaner assembly and the cable from the negative terminal of the battery.

Tips & Warnings

• Use the service manual for your particular vehicle if you have difficulty locating components. You can buy a vehicle service manual at most auto parts stores or consult one for free at most public libraries.

• Make sure you are in a well-ventilated area, away from appliances with open flames like dryers or water heaters, and do not allow smoking near your vehicle whenever you are working on your car’s fuel system.