Ford AA5Z-9F593-C Injector Assembly

To begin, relieve the fuel system pressure and disconnect the cable from the negative battery terminal. For four-cylinder models, remove the intake manifold, disconnect the high-pressure fuel line from the fuel pump and fuel rail, and disconnect the electrical connectors for all wiring associated with the fuel injectors, followed by the four fuel injector electrical connectors. Use a trim removal tool to disengage the retainers securing the wiring harness to the fuel rail, then clean the area around each injector with compressed air. Remove and discard the fuel rail mounting fasteners, then take out the fuel rail and injectors, using new bolts for installation. If the fuel injectors remain in the cylinder heads, use a removal tool to extract them. Remove the old combustion chamber Teflon sealing ring, upper O-ring, and support ring from each injector, taking care not to damage the groove for the seal. Clean the groove and injector shaft thoroughly before installing the new Teflon seal using the recommended special tools or an alternative method with a socket. After installing the new seals, lubricate the new upper O-ring with clean engine oil and install it on the injector, ensuring the O-ring is above the support ring. Clean the injector bores, insert each injector into its bore in the fuel rail, and secure them with retaining clips. Install the injectors and fuel rail assembly on the cylinder head, tightening the mounting fasteners in the correct sequence. For V6 models, remove the appropriate intake manifold, disconnect the fuel supply line and electrical connectors, detach the retainers, and remove the fuel rail and injectors as a single assembly. Release the injector retaining clips and remove each injector, discarding the old O-rings. Coat the new O-rings with clean engine oil and install them on the injectors, then secure the injectors to the fuel rail. Install the intake manifold gaskets if necessary, attach the fuel rail assembly, and tighten the bolts. Finally, reconnect the cable to the negative battery terminal, turn the ignition switch to ON to activate the fuel pump, and check for fuel leaks.