GM 12580649
Fuel Rail

The replacement process of a Fuel Rail assembly requires disconnecting the negative Battery Cable followed by removing the Fuel Injector sight shield. Follow the fuel pressure relief procedure to empty the system pressure before starting the replacement process. The Fuel Rail assembly must be carefully unplugged with caution of the injector electric terminals and spray tip while supporting the rail to protect its components. The opening needs capping while also plugging holes to prevent external contaminants from entering. Follow the gm x 30a engine cleaning solution instructions to cleanse the Fuel Rail assembly whereas liquid cleaning solvents must be avoided. Cut the fuel feed and return pipes (2, 3) off from their connection points with the Fuel Rail and detach the positive crankcase ventilation (PCV) air tube from the cam cover and remove electrical connectors (1) from all fuel injectors before setting down the harness. After removing the engine wiring harness the technician should disconnect it from the Fuel Rail stud, the Fuel Rail attaching studs and the Fuel Rail assembly. The injector lower o-ring seals from each injector end need removal before disposal at the spray tip location. The installation requires removal of fuel injectors to proceed with the new injectors when replacing the Fuel Rail. An application of clean engine oil on the new lower injector o-ring seals follows, using caution to seal the Fuel Rail inlet and outlet ports with plugs for prevention of contamination. Monomolecular cleaning solutions and air pressure should not be used when working with Fuel Rail assemblies. After installing the fuel injectors start by placing new o-ring seals onto the spray tip ends before you install the Fuel Rail. Tighten the Fuel Rail attaching studs to 9 n.m using 80 lb in torque settings. Appy electrical connectors to fuel injectors as well as position fuel feed and return pipes onto the Fuel Rail before reattaching the negative cable to the battery. Turning on the ignition with engine off will validate fuel leak identification during a two-second ignition on period followed by a ten-second ignition off period which should be resumed by turning on ignition with engine off before inspecting for leaks. You should place the Fuel Injector sight shield in its proper position.