First, you need to install the upper O-ring Seal, the plastic Spacer, the retaining Ring, the isolator cup, and the Teflon Seal to the
Fuel Injectors. Then, please install the direct fuel injectors to the cylinder head and install the NEW direct fuel injector hold-down clamps. Finally, you should connect the fuel injector wiring harness electrical connectors to the fuel injectors and install the fuel injection fuel rail assembly.