Fuel Charging and Controls—2.3L

The multiport fuel injection (MFI) system is classified as a multi-point, pulse time, speed density control, fuel injection system. Fuel is metered into each intake port in a sequential firing order. Injectors pulse to follow engine firing order in accordance with engine demand through injectors mounted on a tuned intake manifold.

 WARNING: DO NOT SMOKE, CARRY LIGHTED TOBACCO, OR OPEN FLAME OF ANY TYPE WHEN WORKING ON OR NEAR ANY FUEL-RELATED COMPONENT. HIGHLY FLAMMABLE MIXTURES ARE ALWAYS PRESENT AND MAY BE IGNITED, RESULTING IN POSSIBLE PERSONAL INJURY.

The powertrain control module (PCM) 12A650 also determines and compensates for the age of the vehicle and its uniqueness. The system will automatically sense and compensate for changes in altitude (i.e. from sea level to mountains) and will also permit push-starting the vehicle should it become necessary (manual transmission only).

The fuel charging assembly is the most important component in the fuel system. However, the fuel charging assembly cannot operate efficiently unless all other components in the system are performing correctly.

This Group covers those test and adjustment procedures related directly to fuel injection. Other emission systems related to the fuel system, but not directly to the fuel charging assembly, are covered in the Powertrain Control/Emissions Diagnosis Manual.