How does a fuel injector system work?

A fuel injector system plays a crucial role in the operation of an engine by atomizing fuel, allowing it to mix effectively with air for combustion. This process is vital because proper atomization ensures that the fuel is transformed into a fine mist, which enhances its ability to mix thoroughly with the incoming air during the intake stroke. When the fuel is adequately mixed with air in this manner, it can ignite more efficiently, leading to a more complete combustion process. This efficient combustion results in increased power output and reduces emissions, making it an essential function of the fuel injector system in modern engines.

The other options describe functions that are not associated with a fuel injector system. For example, injecting coolant pertains to cooling systems and is not related to how fuel is delivered to the engine. The option about pumping fuel directly into the tank misrepresents the fuel injection process, as fuel is delivered from the tank to the injectors, not the other way around. Additionally, filtering impurities is a function of fuel filters, not the injectors themselves, which are specifically designed to deliver a precise amount of fuel into the engine's intake manifold or cylinders.