A unit injector is a type of fuel injection system commonly used in diesel engines. It combines the fuel pump and injector into a single unit, allowing for precise control of fuel delivery. This design helps improve engine efficiency and performance by ensuring that the right amount of fuel is injected at the right time. Unit injectors operate under high pressure, which atomizes the fuel for better combustion. They are often found in heavy-duty vehicles and machinery, where reliability and power are essential. This technology is crucial for meeting emissions standards and enhancing overall engine performance.