Sequential Fuel Injection (SFI)

SFI vehicles can operate in one of 2 injection modes: simultaneous or sequential. In simultaneous injection mode, fuel is injected into all cylinders at the same time. In sequential injection mode, injectors are triggered in the firing order. Fuel injectors operate in sequential mode under most conditions. Fuel injection will shift from sequential to simultaneous mode under following conditions: when engine speed is less than 300 RPM, when engine temperature is less than 140°F (60°C), and during starting.