Port Fuel Injection

Port fuel injected vehicles can operate in one of 2 injection modes, simultaneous or sequential. In simultaneous injection mode, fuel is injected into all 4 or 6 cylinders at the same time, or sometimes in pairs. In sequential injection mode, the injectors are triggered in spark plug firing order.

The ECU controls injection duration in accordance with engine conditions to provide efficient engine operation. Data on engine temperature, engine and vehicle speed, intake air volume, throttle position, exhaust oxygen content, and intake air temperature are used by ECU to modify injection pulse width.