GM 12597870
Fuel Rail

A proper replacement of the Fuel Rail assembly starts with applying fuel pressure relief through either ch 48027 (With) or (Without CH 48027. When replacing the Fuel Rail, disconnected fuel feed pipe quick connect fitting at the Fuel Rail then remove positive crankcase ventilation tube from intake duct and Intake Manifold followed by disconnecting Spark Plug Wires from ignition coils. The replacement process starts by disconnection of electrical engine harness connectors from throttle actuator, engine coolant temperature (ECT) sensor, ignition control module wiring harness, manifold absolute pressure (MAP) sensor, fuel injectors, exhaust gas recirculation (EGR) valve, evaporative emission (EVAP) solenoid, and heated oxygen sensor (HO2S) pigtail. The rear engine harness retainers must be removed from around the Fuel Rail and the engine harness branches need to be gathered together before the Fuel Rail can be unfastened with its nuts. Caretfully raise the Fuel Rail through balanced pressure on both rail sides. When substituting the Fuel Rail discard the Fuel Injector retainers as well as the fuel injectors but dispose of the upper o-ring and lower o-ring seals. Application requires injecting engine oil onto new o-ring seals followed by installing them onto fuel injectors while setting the retainer components. Before installation place a lubricant on the lower o-ring seals followed by rail positioning and injector seating. Fasten the Fuel Rail nuts by applying torque of 10 n.m (89 lb in) pattern. The Fuel Rail harness must rest over the engine while retainers need to attach to the Fuel Rail before connecting electrical connectors to fuel injectors and ho2s pigtail among other components in a specific order. The last installation steps should begin with reinstallation of the spark plug wire retainer followed by connecting Spark Plug Wires to ignition coils before installing the pcv tube and reconnecting the fuel feed pipe via its quick connect fitting. Apply the negative Battery Cable before checking for leaks while turning on and off ignition then install the Intake Manifold cover.

The replacement of Fuel Rail assembly requires releasing pressure from the fuel system as the first step. Soak the Fuel Rail assembly in a gm x-30a or equivalent spray type engine cleaner by following the directions in the package but never submerge it completely in cleaning solvents. Remove the quick connect fittings from the Fuel Rail for the fuel feed pipe and pcv air tube from the camshaft cover. The procedure begins with relocating surge tank inlet pipe hose clamps then extracting the hose from both surge tank and engine connection before removing surge tank inlet pipe nuts and the pipe from Fuel Rail studs. Begin by disconnecting electrical connectors from both front and rear fuel injectors and starter solenoid cable then remove the engine harness clip at the Fuel Rail stud and place the harness on the side. To remove the Fuel Rail first undo the bracket retainer nut and each Fuel Rail stud before extraction followed by disposal of the o-ring seals at the spray tip end of each Fuel Injector. When replacing the Fuel Rail you should install the fuel injectors and new o-ring seals before lubricating the lower injector o-ring seals with clean engine oil. Then install the Fuel Rail by tightening the studs to 10 n.m (89 lb in). Position the harness over the engine followed by executing the engine harness electrical plugin activities to both the injectors and starter solenoid cable. Install the Fuel Rail bracket retainer nut to the same torque specification. The surge tank inlet pipe must be reinstalled to the Fuel Rail studs before securing it with nuts while attaching the inlet pipe hose to both engine fitting and surge tank using proper clamp positions. Follow this procedure to attach the pcv air tube to the camshaft cover while connecting the fuel feed pipe to the Fuel Rail before re-attaching the negative battery cable. Complete the examination for fuel leaks by activating and deactivating the ignition twice before reinstalling the sight shield of the Fuel Injector.

First, relieve the fuel system pressure.

Reconnect any remaining electrical connectors, connect the fuel feed pipe to the fuel rail, reconnect the negative battery cable, and inspect for fuel leaks.

Lubricate the lower O-ring seals.

Reconnect the negative battery cable and inspect for fuel leaks by turning the ignition on and off in a specific sequence before checking for any leaks.

Remove the fuel rail bracket retainer nut and the fuel rail studs, then take out the fuel rail and discard the O-ring seals from the spray tip end of each fuel injector.

Clean the fuel rail assembly with a spray type engine cleaner, GM X-30A or equivalent, without soaking it in liquid cleaning solvent.

Disconnect the fuel feed pipe quick connect fitting from the fuel rail and the positive crankcase ventilation (PCV) air tube quick connect fitting from the camshaft cover.

Position the harness over the engine and install the engine harness clip to the fuel rail stud, then connect the engine harness electrical connectors to the rear and front fuel injectors and the starter solenoid cable.