What is the primary function of a fuel injector?

The primary function of a fuel injector is to spray fuel into the combustion chamber. Fuel injectors are essential components in internal combustion engines, specifically in fuel-injected engines. They deliver a precise amount of fuel directly into the intake manifold or combustion chamber, helping to create a homogenous air-fuel mixture. This mixture is critical for the efficient combustion process, which powers the engine.

The process of fuel injection is computer-controlled and optimizes fuel delivery under various operating conditions, improving engine performance, fuel efficiency, and reducing emissions. By atomizing the fuel, injectors ensure a better mix with air, which leads to more complete combustion and prevents issues like misfires or inefficient burning of fuel.

The other options represent functions that, while related to automotive operation, do not describe the primary role of a fuel injector. Cooling the engine typically involves a cooling system with radiators and coolant. Filtering impurities from the fuel is handled by fuel filters, which protect the fuel system and injectors from contaminants. Controlling emissions is a broader function that involves various components, including catalytic converters and other emissions control technologies, rather than solely the fuel injector. Thus, the correct answer focuses specifically on the injector's crucial task of introducing fuel into the engine for combustion.