GM 19417778
Fuel Rail

You must first reduce pressure from the fuel system before starting replacement of the Fuel Rail assembly. Start by disconnecting the fuel return hose/pipe along with the fuel feed hose/pipe from the Fuel Rail with the use of quick connect fitting(s) service (Metal Collar). The protocol starts with ventilating the atmospheric hose both from the air cleaner resonator and the Fuel Pressure Regulator . The procedure requires detachment of the evaporative emission (EVAP) purge hose at both its connections to the throttle control module along with the evap canister purge solenoid valve using the quick connect fitting(s) service procedure which employs a plastic collar. Free the intake manifold and disconnect the Fuel Injector harness connector away from the engine wiring harness electrical connector position. Apply gm x-30a engine cleaner or equivalent to clean both fuelrail assembly components along with the Cylinder Head but avoid liquid soaking of the rail. Use precaution to extract the Fuel Rail from the Cylinder Head while removing its bolts yet maintaining safety of the injector electrical connector terminals and spray tips. Screw caps along with plugging the holes to prevent contamination from entering. Discard one lower o-ring seal from each Fuel Injector by removing it. Proceed to the installation if a replacement of the Fuel Rail is not necessary. First step for disassembly requires removing fuel injectors and Fuel Pressure Regulator before disconnecting the Fuel Injector harness from the Fuel Rail. The procedure starts with inserting the Fuel Injector harness to the Fuel Rail and continuing with fitting the Fuel Pressure Regulator before attaching the fuel injectors . Place virgin gm p/n 9981704 mineral oil on each new lower Fuel Injector O-Ring seal before you position them at the spray tip end of the fuel injectors. Screw the Fuel Rail to the Cylinder Head while inserting fuel injectors spray tips before torquing Fuel Rail mounts to 10 n.m (89 lb in). Mount the intake manifold after linking the Fuel Injector harness connector to the engine wiring harness electrical connector. After fitting the evap purge hose to the throttle control module and the evap canister purge solenoid valve it will be completed by attaching the atmospheric vent hose to the air cleaner resonator and the Fuel Pressure Regulator . The last step involves connecting fuel return hose/pipe and fuel feed hose/pipe to the Fuel Rail with quick connect fittings service (Metal Collars). Before inspecting for leaks, turn the ignition on with an off engine for 2 seconds followed by turning it off for 10 seconds then repeating the process with engine off to examine fuel leakages.

Connect the EVAP purge hose to the throttle control module and the EVAP canister purge solenoid valve, followed by connecting the atmospheric vent hose to the air cleaner resonator and the fuel pressure regulator.