GM 12621662
Fuel Rail

You should start by taking off the air cleaner outlet duct before lowering fuel system pressure with ch 48027 or without it to perform fuel injection Fuel Rail assembly replacement. First remove the engine wiring harness bracket nut while disconnecting all electrical connectors from the evap purge solenoid generator MAP Sensor and ignition coil main electrical connector and electronic throttle control. Proceed by disconnecting and noting the fuel injector electrical connectors before removing any necessary cpa retainers from the unit. All necessary steps include detaching engine wiring harness clips (4 and 6) and the negative Battery Cable stud along with terminals (2 and 3) from the Cylinder Head. You should disconnect the chassis fuel feed pipe as well as the evap tube quick connect fittings while disengaging the evap canister purge solenoid retainer and removing the Fuel Rail bolts. Raise the Fuel Rail assembly with caution while maintaining safety of injector electrical connectors and spray tips before sealing plugged pipe fittings to avoid system contamination. Apply a spray type engine cleaner to the Fuel Rail before you take out the fuel injector retainers and injectors while discarding both the top and bottom o-ring seals (2 and 4). You should first detach the crossover pipe retainer screws and retainers then remove the crossover pipe along with its o-ring seals from the system. Apply clean engine oil to the new o-ring seals before placing them onto the crossover pipe and inserting this pipe between the fuel rails where retainers and screws should be tightened to 3.8 n.m (34 lb in). After applying lubrication to new o-ring seals numbers 2 and 4 the technician installs the rubber seals on the fuel injectors before inserting them into the fuel rails to retain them with proper hardware. Use firm pressure to insert the Fuel Rail onto the intake manifold until all injectors are properly positioned. Install Fuel Rail bolts along with their matching torque to 10 n.m (89 lb in). The evap tube should be connected first followed by the purge solenoid and then the evap canister purge solenoid to the Fuel Rail bracket before installing the chassis fuel feed pipe and evap tube fittings. Reinstall the pcv hose and gather all engine wiring harness branches before using the clip bolt to secure them tightly to 9 n.m (80 lb in). Complete battery connection starts with attaching the negative Battery Cable terminal while installing the ground terminal followed by tightening the negative Battery Cable stud to 25 n.m (18 lb ft). The ignition coil main electrical connector needs to reconnect before installing the cpa retainer while also uniting electronic throttle control and fuel injector connectors properly with full security in place. The installation process ends by joining the MAP Sensor with the generator and evap purge solenoid followed by installing the engine wiring harness bracket nut with 5 n.m (44 lb in) torque and negative Battery Cable reconnection. Leak inspection should occur by turning the ignition on and off. The installation ends with ducting the airflow to the air cleaner after completion.

You must detach the air cleaner outlet duct before starting to replace the Fuel Rail assembly. Use ch-48027 to relieve fuel system pressure or follow the applicable procedure. Start by detaching the engine wiring harness bracket nut before disconnecting the external electrical connectors from the evap purge solenoid, generator and MAP Sensor, evap purge solenoid, generator, ignition coil main connector, electronic throttle control. Start by marking the Fuel Injector electrical connectors for reassembly but disconnecting them from their location. Remove the cpa retainers to disconnect other connectors. Detach the engine wiring harness clips alongside the negative Battery Cable from the right cylinder head. The technician disconnects the quick connect fitting of the chassis fuel feed pipe while also taking off the evap tube quick connect fittings at both the intake manifold and the evap canister purge solenoid. You should first remove the retainer locking the evap canister purge solenoid to the Fuel Rail before removing the Fuel Rail bolts and carefully moving the entire Fuel Rail assembly to protect its injector electrical connector terminals together with spray tips. After cleaning the Fuel Rail users must extract the Fuel Injector retainers and fuel injectors with disposal of original upper and lower o-ring seals (2 and 4). The installation begins with engine oil lubrication of new o-ring seals followed by placement on the injectors before inserting them into the Fuel Rail. Handle the Fuel Rail retainers first before arranging the Fuel Rail on the intake manifold and pushing it to achieve full seating. First install the Fuel Rail bolts while tightening them to 10 nm (89 lb in) then reconnect the evap tube and purge solenoid and the chassis fuel feed pipe by installing the quick connect fitting. Gather the engine wiring harness branches and reinstall the pcv hose before using the clips for connection. The engine wiring harness bracket nut requires installation at 5 nm to 44 lb in torque. At this time, connect the negative Battery Cable while ensuring all electrical connections are correctly in place. The process ends with turning on the ignition to verify for leaks before installing the air cleaner outlet duct.