Ford 4L8Z-9F593-B
Injector

Safety during fuel injector and fuel rail service requires that you keep all areas free of smoking and open flame due to the presence of flammable mixtures. First empty the fuel system pressure then separate the battery ground cable. Start by separating the fuel supply tube quick connect coupling from the fuel rail before detaching both the fuel rail pressure and temperature vacuum tube and electrical connector. The initial step involves disconnecting four fuel injector electrical connectors before removing the nut allowing you to place the radio capacitor to the side. You should remove the wire harness retainer from the valve cover stud bolt followed by disconnecting the two pin-type wire harness retainers which secure the fuel rail. The process of repair begins with removing two fuel rail stud bolts which enables extraction of fuel rail assembly with its injectors. The mechanic should remove and discard eight fuel injector O-ring seals. Install new O-ring seals manufactured from resistant fuel material by oiling them with engine oil before fitting them into the fuel injectors with the retaining clips. Reinstall the combination of fuel rail and injectors while securing them by tightening the two fuel rail stud bolts to 23 Nm (17 lb-ft). The pin-type retainers should be positioned onto the fuel rail and the wire harness retainer should be mounted on the valve cover stud bolt. The radio capacitor needs placement before installation of the nut followed by torque adjustment to 10 Nm (89 lb-in). Among the final tasks is to connect the fuel injector electrical connectors followed by the fuel rail pressure and temperature vacuum tube electrical connector and fuel supply tube quick connect coupling at fuel rail and battery ground cable.

The presence of highly flammable mixtures during fuel injector service requires all workers to stay away from any smoking activities in addition to excluding any lighted tobacco or open flames near fuel-related components to prevent personal injury. The fuel system maintains high pressure after engine shutdown which demands relief before working on any fuel components or fuel lines to prevent injuries. Heavy maintenance of fuel-related components demands that all openings for fuel must be properly sealed with caps or tape or another protective method to defend against contamination until all protective elements are cleared to facilitate installment. Start with removal of the fuel rail before proceeding to remove eight fuel injectors while replacing the O-ring seals with special fuel-resistant ones since regular O-rings need replacement instead of reusability. The installation process ends with new O-rings that received engine oil lubrication according to the reverse order of the removal steps.

Safety precautions when servicing the fuel injector and fuel rail include avoiding all flames and smoking because highly flammable mixtures exist in the system. Relieving the fuel system pressure is the first step because high pressure remains in the system when the engine stands idle. Begin by removing power from the battery ground cable before separating the fuel supply tube quick connect coupling that connects to the rail. The technician should first disconnect the fuel rail pressure and temperature sensor vacuum tube alongside its electrical connector then proceed to the four electrical fuel injector connectors. First secure the radio capacitor nut off and place it aside before detaching the wire harness retainer from the valve cover stud bolt and finally removing the two pin-type wire harness retainers from the fuel rail. To recover the fuel rail and injectors as an assembly you need to remove their two fuel rail stud bolts. The installer should discard eight seals found within the fuel injector O-ring system. The installation requires new seals of specific fuel-resistant material which need to be lubricated with clean engine oil before use. Secure the fuel rail with its injectors through two fuel rail stud bolts attached at 23 Nm torque rating (17 lb-ft). Fasten the two pin-type wire harness retainers onto the fuel rail along with securing the wire harness retainer at the valve cover stud bolt. After placement of the radio capacitor follow up with the installation of the nut while tightening it to 10 Nm resulting in 89 lb-in torque. Conclude this procedure by attaching the four fuel injector electrical connectors and the vacuum tube and electrical connector for the fuel rail pressure and temperature sensor and the fuel supply tube quick connect coupling at the fuel rail and the battery ground cable.

During the repair or replacement of fuel-related components, ensure that all liquid and vapor fuel openings are capped, taped, or otherwise protected to prevent contamination, and remove these protective materials before installation.

It is crucial to avoid smoking or carrying any lighted tobacco or open flames near fuel-related components due to the presence of highly flammable mixtures, which can lead to personal injury.

Begin by relieving the fuel system pressure and disconnecting the battery ground cable.

Disconnect the vacuum hose and electrical connector for the fuel rail pressure and temperature sensor, then remove the wiring harness retainer from the valve cover stud bolt and set it aside.

They can be damaged by fuel, leading to leaks.