Sequential Fuel Injection System
WARNING: This page is about a different car, the 2003 Saturn LW300 and 2003 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.
Fuel injectors are pulsed sequentially in spark plug firing order. Main differences between sequential and simultaneous systems are injectors, wiring and the ECM. Constant fuel pressure is maintained to the injectors. Air/fuel mixture is regulated by amount of time injector stays open (pulse width). Various sensors provide information to the ECM to control pulse width.