GM 12574927
Injector

The Fuel Injector service requires starting with negative Battery Cable detachment followed by fuel system pressure relief. You should first remove the upper manifold assembly while also taking away the fuel meter body assembly. After separating the lower hold down plate and its mounting nuts the poppet nozzle tube should be pulled downward with the help of a small tip punch between injector terminals to remove the component. The assembly process requires selecting the proper injector matching the service application because each unit has individual flow rate calibration. The new injector o-ring seals require application of clean engine oil before their installation onto the injector assembly. The central sequential multiport fuel injection (SFI) Fuel Injector assembly needs to be assembled into the fuel meter body injector socket before tightening the lower hold down plate nuts to 3 n.m (27 lb in). To finish the installation process users must place the fuel meter body assembly together with the upper manifold assembly while reattaching the negative Battery Cable.

Be aware that the engine oil may be contaminated with fuel.

Lubricate the new injector O-ring seals with clean engine oil.

Replace the injector with the lowest drop.

Push the fuel injector into the fuel rail injector socket with the electrical connector facing outward, ensuring the retainer clip locks onto a flange on the fuel rail injector socket.

Lubricate the new injector O-ring seals with clean engine oil and install them on the injector.

Mix 96 ml (3.24 oz) of Top-Engine Cleaner with 864 ml (29.16 oz) of regular unleaded gasoline.

Install the fuel meter body assembly, the upper manifold assembly, and reconnect the negative battery cable.

Be aware that the engine oil may be contaminated with fuel.

Remove the CPA retainers and disconnect the negative battery cable stud and terminal from the right cylinder head, followed by the engine wiring harness clips and the positive crankcase ventilation (PCV) hose.