Fuel-injector performance loss and failure is due to deposits and part wear. Even clean fuel injectors will eventually wear out. When injectors are degraded, performance loss, power loss and even engine damage can occur. When fuel injectors begin to fail, or are in a failure condition, fuel-to-air ratios during combustion can result in too lean or too rich conditions. This may result in engine or exhaust system damage. Replacing your Ford fuel injectors can restore lost power, restore lost fuel economy and even prolong the life of your engine.
Depressurise the fuel system to allow fuel rail removal.. Locate the fuel inertia cut-off switch on your Ford. The location can be found in the owner's manual. Remove the electronics plug from the inertia cut-off switch, using pliers if necessary. Attempt to start the engine to use the fuel in the fuel rail. Repeat the ignition attempt twice.
Remove the negative battery cable from the vehicle's battery before working on the engine or with fuel-related components.
Remove any external components, such as the air intake and any electronics, to allow access to the fuel rails. The fuel rails will attach to the tops of the fuel injectors.
Remove the electronics plug from the injector to be replaced. Squeeze the sides of the plug to release the latches and pull away from the injector.
Remove the bolts securing the fuel rail to the engine. Remove the fuel rail from the injectors requiring replacement. On some Ford vehicles, such as V model engines, the fuel rail must be removed from a bank of injectors to allow access to a single injector. It may be necessary to rock the fuel rail back and forth to allow the top o-ring of the injector to slip from the fuel rail.
Remove the bolt securing the injector to the engine. Store the bolt in a place where it will not fall into the cylinder during fuel injector replacement.
Pull the injector from the engine by pulling upwards and rocking until the injector pops out of the hole. Ensure both o-rings are accounted for the injector; o-rings will be found on the top and bottom of the injectors.
Replace all top o-rings on every injector removed from the fuel rail. Replace the bottom o-rings on injectors removed from the engine. The o-ring is flexible like a tight rubber band and can be slipped from the top or bottom of the fuel injector. Add a small amount of new motor oil to each o-ring before installing to protect the surface during installation of the fuel injector into the engine or fuel rail.
Re-install the fuel injector by pushing the injector downward into the hole. The fuel injector should resist removal once properly installed.
Re-attach the retaining bolts, fuel rails, fuel rail retaining bolts and any external components removed to allow access.
Re-attach the fuel inertia switch plug. Re-pressurise the fuel system by turning the ignition key to "electronics-only" mode to allow the fuel pump to pressurise the line. Wait 3 to 5 seconds turn the key to the "off" position, and then repeat the procedure twice. Start the engine to verify installation.
If your engine is hot, it may be more difficult to remove some parts and components because of metal expansion. Waiting until the engine is cooled will also reduce the likelihood you burn yourself against hot metal engine parts. Use Nitrile gloves when working with fuel related components, as latex will dissolve when exposed to gasoline.
Work in a well-ventilated area free of sparks or fire.