GM 90411881
Fuel Rail

Service of the Fuel Rail begins with relieving fuel system pressure while masking the intake ducts after upper plenum removal to stop foreign objects from entering which could result in serious engine damage. Proceed by taking out the intake plenum before detaching the Fuel Rail intermediate lines (supply-return) and moving them away from the Fuel Rail. To service the Fuel Rail start by removing bolts from its bracket which is close to fuel supply-return lines while unclipping the harness from the rail and placing it to one side before disconnecting Fuel Injector electrical connectors. Perform hose disconnection of the atmospheric vent for the fuel pressure regulator before extracting all Intake Manifold bolts which attach to the Fuel Rail. Obtain compressed air to clean the portion where injectors reach the intake casting followed by taking out the Fuel Rail assembly and Fuel Injector retainers. The first step involves extracting the injectors from their position on the Fuel Rail before proceeding with fuel pipe cleaning with an emery cloth that avoids damaging the o-ring sealing surface. Using a clean shop towel you should clean and check the tube ends for damage before inspecting all connections for dirt and burrs. Replace parts or clean the components when necessary. The old o-rings must be thrown away from the injectors before applying lubricant for new o-ring installation. The Fuel Rail installations require new retainer clips which the injectors should face perpendicular to the crankshaft centerline for proper alignment. Secure the Intake Manifold with the install Fuel Rail by bolting the attaching parts to 8 n.m (71 lb in). Complete the reconnection process of the fuel pressure regulator half of the atmospheric vent pipe followed by attaching the Fuel Rail electrical connectors along with its harness and bolted down the Fuel Rail bracket at the supply-return line positions while torque values are set at 8 n.m (71 lb in). Install the intake plenum followed by a connection of the negative Battery Cable and tighten the Fuel Rail intermediate lines to 15 n.m (11 lb ft). To complete the procedure end with engine cranking until it starts while also checking for fuel leaks before finishing.

Relieve the fuel system pressure and remove the intake plenum.

Remove the retainers from the fuel injectors and take out the injectors from the fuel rail.

Disconnect the fuel injector electrical connectors, unclip the harness from the fuel rail, and disconnect the atmospheric vent hose from the fuel pressure regulator.