Fuel Metering System Description
DESCRIPTIONThe Sephia runs on a sequential multiport fuel injection (SFI) system. These systems supply the engine with the air/fuel mixture necessary for combustion. The air induction system and fuel injection system work in conjunction with an electronic engine control system which consists of various sensors, switches and an engine control module (ECM). All sensors and switches are connected to the ECM which interprets the data it receives and computes the timing and the duration so that the electrically operated injectors can be energized.
The basic fuel requirement of the engine is determined from the data supplied to the ECM by the mass air flow (MAF) sensor, which measures the amount of air being drawn into the engine. Other sensors and switches are used to measure:
- Air temperature
- Atmospheric pressure
- Coolant temperature
- Engine speed
- Exhaust oxygen content
OPERATION
The various sensors and switches detect any changes in the operating conditions and send signals to the ECM. This permits the ECM to control the opening duration (pulse width) of the injectors and maintain optimum exhaust emission control and engine performance for all operating conditions.