General System Description

PURPOSE
To provide the engine with controlled air and fuel intake resulting in precise control of engine speed and combustion efficiency.


OPERATION
(Electronic) Multiport Fuel Injection (MFI) delivers precise amounts of fuel to the air intake charge thus providing the means to control the air/fuel mixture delivered to the engine. This results in optimum engine performance and lowest possible levels of unburned hydrocarbons, carbon monoxide and nitrogen oxides in the exhaust gases.
Fuel pressure across the fuel injectors is maintained by a pressure regulator. Because fuel pressure is a constant when fuel demand is not, the system includes a fuel return line that allows excess fuel to flow back through the regulator to the fuel tank. The amount of fuel the injectors will spray under a particular operating condition is determined by a Powertrain Control Module Engine (PCME). The PCME receives signals from sensors that monitor airflow to the engine, engine coolant temperature, engine vacuum conditions, oxygen content, etc. The PCME determines injector "ON time" based on sensor inputs and the mapped fuel curve within PCME program memory.

The Air Intake System provides the control of engine speed based on inputs from either the vehicle operator via the accelerator linkage and/or the PCME via the idle speed control system.

View: Fuel System:

CONSTRUCTION
The fuel delivery system consists of:
- High pressure electrical fuel pump mounted in-tank
- Fuel filter
- Fuel pressure regulator
- Fuel pressure regulator control solenoid valves
- Fuel injectors
- Fuel pump relay
- Fuel tank
- Delivery pipe

The air induction system consists of:
- Accelerator pedal/linkage system
- Throttle body assembly
- Idle speed control system
- Intake manifold assembly
- Air cleaner assembly.
- Variable inertia charging system