GM 12587074
Fuel Rail

The primary step for replacing the Fuel Rail assembly involves removing fuel system pressure from the components. The repair area needs complete cleaning around all fuel pipe systems and evaporative emission (EVAP) unit connections to prevent contamination. The technician must disconnect both the fuel feed pipe from the Fuel Rail and the evap pipe from the evap canister purge solenoid valve. Remove the upper Intake Manifold and disconnect first the engine harness electrical connector from the Fuel Injector harness electrical connector and then disconnect the Fuel Injector harness electrical connector from the engine coolant temperature (ECT) sensor and the camshaft position (CMP) sensor. Competent technicians uninstall the Fuel Rail's bolts and remove the rail before extracting o-ring seals from each injector's spray tip to take out the fuel injectors from their mounting position on the rail. Execute careful handling of all fuel system components by plugging both ports of the Fuel Rail before installation in order to prevent contamination. New lower o-ring seals should be installed to the fuel injectors before use and gm p/n 12345616 (Canadian P/N 993182) or an equivalent lubricant should be applied to injector tip o-rings. Raw Fuel Injector bores receive the fuel injectors followed by Fuel Rail pressuring until each injector reaches full seating. Place the Fuel Rail bolts on the mounting points before tightening them to 10 n.m (89 lb in). Conduct this connection by installing the Fuel Injector harness electrical connector first to the cmp sensor and ect sensor then to the engine harness electrical connector. The technician should reinstall the upper Intake Manifold while he reconnects the evap pipe to the evap canister purge solenoid valve before connecting the fuel feed pipe to the Fuel Rail. To finish the service the technician must re-establish the negative Battery Cable and perform a fuel leak inspection through a sequential ignition turn-on sequence of 2 seconds off for 10 seconds followed by a third ignition turn-on.

The replacement of Fuel Rail assembly starts by reducing pressure within the fuel system. The black o-ring must be placed above the brown one while installing the fuel injector o-rings because these rings differ in their material composition even though they have identical dimensions. Service activities require proper measures for blocking fuel pathways from pollutants by using plugs for holes and caps for fittings. Engine fuel pipe connectors should receive cleaning before separation to prevent leakage. Trim off the fuel feed pipe retaining clip before extracting the engine fuel feed pipe from its connection to the Fuel Rail. Unplug the evaporative emission (EVAP) pipe from the evap canister purge solenoid valve. After that disconnect and remove the upper Intake Manifold. The service requires separation of the fuel injector harness together with the Coolant Temperature Sensor and Camshaft Position Sensor electrical connectors and the main fuel injector electrical connector. The procedure starts with Fuel Rail retaining bolt removal followed by the Fuel Rail assembly extraction. The technicians replace each injector's spray tip-end injector o-ring seal after the extraction. Proceed with the fuel injector replacement method when needed. For fuel injector nozzle installation into the lower Intake Manifold bores use gm p/n 12345616 lubricant along with canadian p/n 993182. The Fuel Rail should be pressed while moving it to achieve proper injector seating followed by tightening Fuel Rail bolts to 10 n.m (89 lb in). Reconnect all electrical connectors and apply gm p/n 12377900, (Canadian P/N 10953529) lubricant to the fuel injector electrical connectors before finishing. Connect the Fuel Rail first to its engine fuel feed pipe then link the evap pipe to the evap canister purge solenoid valve before placing back the upper Intake Manifold. Check for fuel leaks by keeping the ignition on for two seconds followed by turning it off for ten seconds and on one last time while inspecting for any leakage.

Use care with the fuel injector electrical connectors, tips, and O-rings, and plug the inlet and outlet ports of the fuel rail to prevent contamination.

Pull up the lock release of the fuel injector electrical connectors, depress the lock tabs, and disconnect the connectors.

Install the fuel injectors, ensuring they are positioned downward as you lower them into the cylinder head ports.

Connect the negative battery cable and inspect for fuel leaks by turning ON the ignition with the engine OFF for 2 seconds, turning OFF the ignition for 10 seconds, turning ON the ignition again, and checking for any leaks.

Turn ON the ignition for 2 seconds, turn it OFF for 10 seconds, and then turn it ON again, checking for any leaks.