Fuel Systems: Description: Notes

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The fuel system is comprised of two sub-systems. The fuel supply system and the fuel metering system. The correct amount of fuel can not be delivered to the engine cylinders without a constant supply of air from the air intake system. The air intake system provides measured clean air to each cylinder for proper mixture with the pressurized fuel. The Powertrain Control Module (PCM), along with the information sensors and switches, controls the activity between all three systems.

The fuel supply system is a returnless on-demand design, that reduces evaporative emissions. The fuel metering system is a Sequential Fuel Injection (SFI) design. The function of the fuel metering system is deliver the correct amount of fuel to the engine under all operating conditions. The main component of the vehicle's fuel metering system is the fuel injectors. There is one fuel injector for each cylinder. The fuel injectors are controlled sequentially by the PCM. The PCM bases the control of the fuel injectors on several important engine parameters. These engine parameters include the following:

Mass Air Flow (MAF) sensor.
Intake Air Temperature (IAT) sensor.
Engine Coolant Temperature (ECT) sensor.
Throttle Position (TP) sensor.
Engine speed (RPM).
Heated Oxygen Sensor (HO2S).

The engine is designed to use only premium unleaded fuel. Unleaded fuel must be used for proper emission control system operation. Using unleaded fuel will also decrease spark plug fouling and extend engine oil life. Leaded fuel can damage the emission control system. The use of leaded fuel can result in the loss of emission warranty coverage. The vehicle fuel system is equipped with an evaporative emission control system that minimizes the release of fuel vapors to the atmosphere.

The vehicle fuel system is equipped with an evaporative emission control system that minimizes the release of fuel vapors to the atmosphere.