Variable Induction System: Description and Operation

Intake Air System:

OVERVIEW
The Intake Air system provides clean air to the engine, optimizes air flow and reduces unwanted induction noise. The Intake Air System consists of an air cleaner assembly, resonator assemblies and hoses. The main component of the intake air system is the air cleaner assembly. The air cleaner assembly houses the air cleaner element that removes potential engine contaminants, particularly abrasive types. The Mass Air Flow (MAF) sensor is attached internally or externally to the air cleaner assembly and measures the quantity of air delivered to the engine combustion chamber. The MAF sensor can be serviced or replaced as an individual component. The intake air system also contains a sensor that measures the intake air temperature. (Refer to Electronic EC Hardware PCM Inputs for additional information on the MAF and IAT sensors). Air induction resonators can be separate components or part of the intake air housing (i.e., conical air cleaner). The function of a resonator is to reduce induction noise. The air induction components are connected to each other and to the throttle body assembly with hoses.

The Escort/Tracer 2.0L (2V) intake air sub-system is the IMRC electric actuated system.


This subsystem is used to provide increased intake airflow to improve torque and performance The overall quantity of air metered to the engine is controlled by the throttle body.

Intake Manifold Runner Control (IMRC) - Electric Actuated:

INTAKE MANIFOLD RUNNER CONTROL ELECTRIC ACTUATED SYSTEM
The Intake Manifold Runner Control (IMRC) Electric Actuated system consists of a remote mounted motorized actuator with an attaching cable for each housing on each bank. Some applications will use one cable for both banks. The cable attaches to the housing butterfly plate levers. The Escort/Tracer 2.0L (2V) IMRC uses a motorized actuator mounted directly to a single housing without the use of a cable. Each IMRC housing is an aluminum casting with two intake air passages for each cylinder. One passage is always open and the other is opened and closed with a butterfly valve plate. The housing uses a return spring to hold the butterfly valve plates closed. The motorized actuator houses an internal switch or switches, depending on the application, to provide feedback to the PCM indicating cable and butterfly valve plate position.

Below approximately 3000 rpm, the motorized actuator will not be energized. This will allow the cable to fully extend and the butterfly valve plates to remain closed. Above approximately 3000 rpm, the motorized actuator will be energized. The attaching cable will pull the butterfly valve plates into the open position.
1. The PCM uses the TP sensor and CKP signals to determine activation of the IMRC system. There must be a positive change in voltage from the TP sensor along with the increase in rpm to open the valve plates.
2. The PCM uses the information from the input signals to control the IMRC motorized actuator based upon rpm and changes in throttle position.
3. The PCM energizes the motorizes actuator to pull the butterfly plates open with the cable(s).
4. The IMRC housing contain butterfly plates to allow increased air flow.