Mercury 5W7Z-9F792-AC Fuel Rail

The first step in removing the air intake plenum and throttle body on a 5.0L engine involves disconnecting the negative battery cable. Also, unplug electrical connectors at the air bypass valve, throttle position sensor, and EGR position sensor. Disconnect the accelerator cable and transmission linkage from the throttle body assembly, remove the accelerator cable/TV cable bracket from the intake manifold, and label and detach vacuum lines from the upper intake manifold vacuum tree, EGR valve, and fuel pressure regulator. Make sure to disconnect the PCV system or any canister purge line if it is present and also downsize the water pipes of spacer coolant lines for EGR. Unbolt six (6) upper manifold retaining bolts to separate the upper manifold and throttle body as an assembly from the lower manifold. Ensure the gasket is in place during installation, attach new gasket(s) onto lower intake mounting face, and snug up air intake plenum with throttle body assembly by using six (6) upper manifold retaining bolts right up to the recommended torque value.

Relieve fuel pressure, remove the air intake plenum assembly on 5.0L engines or the air intake assembly on 4.6L engines, and remove the fuel rail assembly. Detach the electrical connectors from the injectors, remove the injectors, inspect and replace injector O-rings and other components as needed. Lubricate new O-rings with oil before installation and twist to install the injectors. The remainder of the installation is the reverse of removal.