Fuel Injection System - DFI: Description
The Digital Fuel Injection (DFI) system uses a speed/density fuel system which accurately controls air/fuel mixture providing maximum engine performance, while minimizing exhaust emissions.
The system consists of fuel delivery, air induction, data sensors, Electronic Control Module (ECM), Idle Speed Control (ISC), and system diagnostics.
The ECM, an on-board computer, monitors engine operations and environmental conditions. Fuel is supplied to engine through 2 electronically pulsed (timed) injector valves located in throttle body. The ECM controls amount of fuel metered through injector valves based upon engine demand (sensor input).
NOTE:
Primary sub-systems which affect fuel system operation will be covered in this section: fuel delivery, air induction, Idle Speed Control (ISC), Electronic Control Module (ECM) and data sensors. See appropriate GENERAL MOTORS DFI CONTROL SYSTEM in COMPUTERIZED ENGINE CONTROLS section for information on additional systems which are also controlled by the ECM.