General System Description

PURPOSE
The function of the fuel metering system is to deliver the correct amount of fuel to the engine under all operating conditions. Fuel is delivered to the engine by eight individual fuel injectors mounted in the intake manifold near each cylinder.

OPERATION
The main control sensors are the two Heated Oxygen Sensors (H02S) located in the exhaust system. The HO2S tells the Powertrain Control Module (PCM) how much oxygen is in the exhaust gas. The PCM changes the air/fuel ratio to the engine by controlling the fuel injectors. The best mixture to minimize exhaust emissions is 14.7 to 1, which allows the warm-up three-way catalytic converters to operate the most efficiently. Because of the constant measuring and adjusting of the air/fuel ratio, the fuel injection system is called a "Closed Loop" system.