Fuel Delivery and Air Induction: Description and Operation

FUEL DELIVERY
The Sequential Multiport Fuel Injection (SFI) provides the fuel/air mixture needed. The induction system is mounted on an aluminum intake manifold. Fuel flow is as follows:
1. Fuel is supplied from the vehicle fuel tank by a high-pressure electric fuel pump mounted in the fuel tank.
2. The fuel is then filtered and sent to the fuel injection supply manifold.
3. A fuel pressure regulator on the fuel injection supply manifold controls the fuel delivery pressure at a constant 269 kPa (39 psi).
4. Excess fuel supplied by the fuel pump, but not needed by the engine, is returned to the fuel tank by a fuel return line.

Fuel Injectors
The eight fuel injectors are:
- Positioned so that their tips direct fuel just ahead of the engine intake valves.
- Connected in parallel with the fuel pressure regulator.

AIR INDUCTION
Components
All engines are equipped with:
- Replaceable dry-type air cleaner element (ACL).
- Engine air tray, is attached to the RH front fender apron.
- Mass Air Flow (MAF) sensor.

Operation
The air induction system supplies clean air to the throttle body. It operates as follows:
- Outside air enters from an air intake in the engine air cleaner through an opening in the front fender apron.
- In the engine air tray, air is filtered by the air cleaner element.
- From the engine air cleaner, the filtered air travels through the mass air flow sensor and air cleaner outlet tube to the throttle body.
- The Positive Crankcase Ventilation (PCV) system is also supplied clean air through a fitting on the air cleaner outlet tube.