Fuel Injection System - Multi-Point: Description
The 3.0L engine with Multi-Point Fuel Injection is used on the 1988 Caravan and Voyager. The Single Module Engine Controller (SMEC) is the center of the system. The SMEC processes various sensor and switch inputs used to monitor several engine and vehicle operating conditions and then assigns control signals to all output devices. These control signals are used to control the injector pulse width, spark advance, idle speed and other engine functions.
The SMEC tests many of its own input and output circuits. If a fault is found in a major circuit, a memory code is stored in the system. These codes may be accessed using diagnostic readout equipment or through the instrument panel "CHECK ENGINE" light. For further information, see CHRYSLER MOTORS 3.0L ENGINE CONTROL in the COMPUTERIZED ENGINE CONTROLS section.
Fuel injectors are mounted in each branch of the intake manifold. The throttle body includes an air by-pass automatic idle system, operated by an Automatic Idle Speed (AIS) motor.