GM 12621668
Fuel Rail

The first step to replacing the fuel injection Fuel Rail assembly requires removal of the air cleaner outlet duct. The recommended procedure involves using the fuel pressure relief tool (CH-48027) to empty fuel system pressure yet it can be omitted when appropriate. First remove the engine harness bracket nut while you disconnect connections from the evap purge solenoid, generator and MAP Sensor, ignition coil main electrical connector and all fuel injectors. First mark the Fuel Injector electrical connectors for reassembly then lift the cpa retainer while pressing its tab followed by disconnection of the Fuel Injector electrical connectors. First disconnect the electronic throttle control from the retainer along with other remaining fuel injectors' electrical connectors. Unclip all wiring from the right Cylinder Head while also removing its negative Battery Cable. Chassis fuel feed pipe quick connect fitting must be removed from the Fuel Rail as well as the evap tube quick connect fittings at the Intake Manifold and the evap canister purge solenoid. Remove the Fuel Rail bolts after disengaging the retainer which connects the evap canister purge solenoid to the Fuel Rail and extracting the evap tube together with the purge solenoid. The removal process requires the Fuel Rail assembly to be extracted carefully to prevent damage to both injector electrical connector terminals as well as spray tips while using caps to block fittings from contamination. If cleaning the Fuel Rail is needed raise it evenly from both sides until all injectors are removed before taking away the Fuel Injector retainers along with the fuel injectors. Discard the upper and lower o-ring seals (2 and 4). Before installation, use engine oil to lubricate new Fuel Injector o-rings before installing them on the injectors which need to be positioned into the fuel rails. When installing Fuel Injector retainers position them accordingly while proper lubrication should be maintained for lower o-ring seals. After completing the Fuel Rail position onto the Intake Manifold ensure full seating by pushing down firmly and install the Fuel Rail bolts before tightening them to 10 nm (89 lb in). Connect the evap tube and purge solenoid before you join both ends of the evap chassis tube to its respective fittings: one at the evap canister purge solenoid and the other at the Intake Manifold. Connect the Fuel Rail to its chassis fuel feed pipe quick connect fitting, also install the pcv hose. Move all engine wiring harness branches into correct positions above the engine before clamping the harness with the generator bracket using the designated clip bolt tightened to 9 nm (80 lb in). Reinstall the terminal of the negative Battery Cable and the engine wiring harness ground terminal to the right Cylinder Head while installing the negative Battery Cable stud with torque set to 25 nm (18 lb ft). Secure the engine wiring harness electrical connectors by attaching them to the ignition coil main electrical connector and electronic throttle control as well as the fuel injectors while making sure the cpa retainers stay locked into place. The engine wiring harness bracket requires a nut installation to 5 nm (44 lb in) with the MAP Sensor and generator and evap purge solenoid already connected. After reconnecting the negative Battery Cable the technician follows the specified ignition on/off testing procedure to inspect for leaks and installs the air cleaner outlet duct.

The replacement of the fuel injection Fuel Rail assembly should start by removing the air cleaner outlet duct first. To start the replacement you should first reduce fuel system pressure then remove the bracket nut that holds the wiring harness engine while disconnecting harness wires from the evap purge solenoid and MAP Sensor along with fuel injectors and evap connection to the ignition coil main electrical connector. Moreover, label all disconnected connectors for reinstall by position. First detach the ignition coil bracket stud clip from its harness location and after that remove the heater hose bracket nut while also taking off its bracket. Position the bracket away from the work area. Disassemble the procedure by removing the quick connector fittings between the Fuel Rail and chassis fuel feed pipe as well as between the evap canister purge solenoid and intake manifold evap tube and chassis evap tube. First remove the evap canister purge solenoid retainer from its position between the Fuel Rail then take out the evap tube together with the purge solenoid followed by removing the Fuel Rail bolts. The removal process of the Fuel Rail assembly should be done carefully to prevent damaging injector electrical connectors or spray tips while fittings need caps for preventing fuel contamination. Clean the Fuel Rail when needed before removing the Fuel Injector retainers and extract the fuel injectors while discarding both upper and lower o-ring seals (2 and 4). You need to lubricate new o-ring seals of the fuel injectors with engine oil before installing them onto the injectors and finally securing the fuel injectors into the rail by adding the fuel retainer units. The procedure requires you to push the Fuel Rail firmly onto the intake manifold after applying sufficient lubrication to the lower o-ring seals. First install the Fuel Rail bolts with a torque of 10 nm followed by attaching the evap tube and purge solenoid and then finish by connecting the chassis evap tube quick connect fittings at the respective locations on evap canister purge solenoid and intake manifold. After connecting the Fuel Rail with the chassis fuel feed pipe quick connect fitting, install the pcv hose followed by gathering the engine wiring harness branches over the top of the engine. First insert the engine wiring harness clip followed by bolt installation at 9 nm (80 lb in), next position the heater hose bracket at its ignition coil bracket stud and tighten the nut to 9 nm (80 lb in). Install the cpa retainer while connecting the engine wiring harness electrical connector to the main electrical connector of the ignition coil. Reattach the engine wiring harness electrical connector to the electronic throttle control. Connect the Fuel Injector electrical connectors on the engine harness with proper cpa retainer insertion at one click before attachment then complete cpa retainer push at one click for final installation. The procedure requires installing clips from the engine wiring harness to the ignition coil bracket stud followed by connecting engine wiring harness electrical connectors to the MAP Sensor and evap purge solenoid. The engine wiring harness bracket nut needs installation before tightening to 5 nm (44 lb in) followed by connecting the negative Battery Cable. After turning the ignition on with an off engine for two seconds you should deactivate it for ten seconds and re-activate it with an off engine to check for any indications of leakage. Set up the air cleaner outlet duct as the last step.

Remove the fuel injector harness clips from the fuel rail, take out the harness, remove the fuel injector retainers, and the fuel injectors, followed by the fuel injector upper O-ring seals.