Relieve the system fuel pressure, then disconnect the cable from the negative battery terminal. For 4.2L V6 models, disconnect the fuel supply line spring-lock coupling from the fuel rail, the vacuum hose, and the electrical connector from the Fuel Rail Pressure Temperature (FRPT) sensor. Disconnect the electrical connectors from all six fuel injectors, detach the injector wiring harness retainers from the fuel rail, and remove the four fuel rail bolts. Remove the fuel rail and injectors as a single assembly, grasp each fuel injector firmly, and pull it out of the fuel rail. Remove the two old O-rings from each injector and install new upper and lower O-rings. Installation is the reverse of removal, ensuring to tighten the fuel rail mounting bolts to the specified torque. For 4.6L V8 models, remove the air intake duct, unscrew the threaded fitting at the upper end of the Exhaust Gas Recirculation (EGR) pipe, disconnect the power brake booster hose, and disconnect the electrical connectors from the throttle position sensor and electronic throttle control. Disconnect the electrical connector and vacuum hose from the EGR module, disconnect both ends of the PCV system's fresh air inlet hose, and remove the throttle body spacer and throttle body as a single assembly. Disconnect the electrical connector from the IPR sensor or the injection pressure and temperature sensor, disconnect the electrical connectors from the eight fuel injectors, and remove the fuel rail and injectors as a single assembly. For 5.4L V8 models, remove the air intake duct and air filter housing, disconnect the EVAP purge line quick-connect coupling, and disconnect the electrical connector from the heated PCV valve. Disconnect the quick-connect coupling for the Vapor Management Valve and the throttle position sensor electrical connectors. Remove the fuel rail and injectors as a single assembly, remove the old O-rings from each injector, and install new O-rings, applying clean engine oil to each upper and lower O-ring before installation. For 3.7L V6 and 5.0L V8 models, remove the upper intake manifold, detach the fuel feed line from the fuel rail, and disconnect the electrical connectors from the injectors. Remove the fuel rail and injectors as a single assembly, remove the old O-rings, and install new O-rings with clean engine oil. For 6.2L V8 models, disconnect the air intake duct and adapter from the throttle body, detach the fuel feed line from the fuel rail, and disconnect the electrical connectors from the injectors. Remove the fuel rail and injectors as a single assembly, remove the old O-rings, and install new O-rings with clean engine oil. For 3.5L V6 models, drain the cooling system, remove the intake manifold, detach the hoses from the thermostat housing, and remove the coolant pipe. Remove the high-pressure fuel tube bracket fasteners, detach the high-pressure fuel tube from the fuel rails and pump, and disconnect the fuel injector harness electrical connectors. Clean the valley between the cylinder banks, remove the fuel rail mounting bolts, and detach the left and right fuel rails and injectors. Clean the injector bores, remove the old combustion chamber Teflon sealing ring and O-rings, and install new Teflon seals using special tools or a socket method. Install the new support ring and lubricate the new upper O-ring with clean engine oil before installing the injectors in the cylinder head. Install a new spring steel retainer on each injector, install the fuel rail, and tighten the bolts to the specified torque. Clean the high-pressure fuel line fittings, apply clean engine oil to the threads, and install the new high-pressure fuel line. Install the thermostat housing and coolant crossover pipe, ensuring to tighten the bolts to the specified torque, and refill the cooling system.
Posted by FordPartsGiant Specialist 
