The injector clamp (or clip) is a small metal locking device that secures the fuel injector to the fuel rail. While the fuel rail itself is bolted down, the clamp ensures the injector doesn’t back out or twist under the high pressure of the fuel system. It aligns the injector perfectly with the intake port. If a clamp is bent, broken, or missing, the injector may unseat due to vibration or pressure, leading to a massive fuel leak. These are often made of spring steel and are specific to the vehicle make and model.