Sequential fuel injection is an advanced fuel-delivery system that supplies petrol to each engine cylinder at a precisely timed moment. Unlike older injection methods, it coordinates injector operation with the engine’s firing order, improving combustion efficiency and fuel control.
By delivering the correct fuel quantity for every combustion cycle, sequential fuel injection can enhance throttle response, reduce emissions, and support better fuel economy. Its operation depends on sensors and the engine control unit to maintain accurate air–fuel ratios.
Sequential fuel injection delivers fuel to each engine cylinder individually, timed according to the cylinder’s intake cycle. The electronic control unit uses signals from sensors to determine when each injector should open.
Unlike simultaneous injection systems, which activate several injectors together, sequential fuel injection coordinates delivery with crankshaft position. This allows fuel to enter each cylinder shortly before or during its intake event.
The system can adjust injector timing and pulse duration according to engine speed, load, coolant temperature, throttle position, and oxygen-sensor feedback. These adjustments help maintain the intended air–fuel mixture under changing operating conditions.
Sequential fuel injection can support smoother engine operation, improved emissions control, and efficient fuel use. Its performance depends on accurate sensors, clean injectors, proper fuel pressure, and reliable electronic control.