What tells the injectors to fire on a Subaru engine?

In a Subaru engine, the fuel injectors are controlled by the Engine Control Unit (ECU), which uses input from various sensors to determine the optimal timing and amount of fuel to inject. The ECU processes data from sensors like the mass airflow sensor, throttle position sensor, and crankshaft position sensor to manage fuel delivery. When the ECU decides it's time to inject fuel, it sends an electrical signal to the injectors, causing them to open and deliver the required amount of fuel into the combustion chamber. This precise control helps optimize engine performance and efficiency.