Sequential Fuel Injection (SFI): Notes
WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
The ECM controls the fuel injectors based on information that the ECM receives from several information sensors. Each injector is fired individually in the engine firing order, which is called sequential fuel injection. This allows precise fuel metering to each cylinder and improves the driveability under all of the driving conditions.
The ECM has several operating modes for fuel control, depending on the information that has been received from the sensors.