When it comes to replacing and putting back the fuel rail and injectors on a 6-cylinder engine, it is important to note that, injectors draws current from the DME main relay while the
Engine Control Module controls their engagement by turning 'on' the ground circuit for injector valve solenoids and regulating the length of time the injector is 'open' in order to control the ratio of air to fuel. Get access to them by removing the air intake hood at top of radiator and the upper engine plastic panels. A fast assessment can be done by starting the engine and putting a screw driver or stethoscope on each of the injectors to feel a vibration or hear a buzzing sound then turn the engine off. Remove the battery negative cable in the cargo compartment, be sure to read the battery disconnection caution before proceeding. Disconnect and remove the following parts from the plenum: resonance valve electrical connector, oxygen sensor connectors, intake air temperature electrical connector, manifold vacuum line, and VANOS solenoid electrical connector; also remove and save the plenum seal; note the position for the oxygen sensor connectors. Remove fuel injector electrical connectors by unscrewing the wire lock clips with a small screwdriver then remove the connector loom and put it aside. It helps to unscrew the Schrader valve cap on the fuel rail and the fuel tank cap to let the pressure out and you use short shot of compressed air to push fuel back into the tank. Insert the special tool into the locking clip of the fuel line fitting at the rear of the manifold, pull to disconnect the fuel supply line from the fuel rail and then remove the mounting bolts of fuel rail. Unbolt and remove the fuel rail and injectors from the manifold; unbolt the fuel line support bracket at the rear of the intake manifold and gently pull out the fuel line(s) while raising the fuel rail. If possible, a single injector needs to be replaced, the retaining clip of that injector has to be removed and the injector is pulled off the rail. For removal, follow the installation process but in reverse, make sure to fit new sealing O-rings on the injectors, lightly lubricate them as it helps in installation, make sure that electrical connections and the injectors are well fixed before fixing fuel rail mounting bolts, check rubber O-rings on fuel line and replace if necessary and also check and replace wire ties. Last of all, scan for DTCs and then clear and erase the memory of the ECM.