Overview of the Intake Manifold Runner Control (IMRC) and Intake Manifold Tuning Valve (IMTV) Systems

There are 3 basic types of intake air subsystems:

• IMRC electric actuated system
• IMRC vacuum actuated system
• IMTV

There are several different styles of hardware used to control airflow within the engine air intake system. In general, the devices are defined based on whether they control in-cylinder motion (charge motion) or manifold dynamics (tuning).

The IMRC is a charge motion device that modifies the air charge motion in the manifold. The IMRC control valve is located close to the intake valve/cylinder head. The IMRC actuator can be either electric or vacuum controlled. The IMRC system must have a monitor feedback system in order to meet OBD II regulations.

The IMTV is a manifold tuning device that effects the air flow volume of the manifold by connecting multiple plenums or inlets within the manifold system. The IMTV control valve is located in the center of the intake manifold away from the intake valve or cylinder head. The IMTV actuator can be either electric or vacuum controlled. The IMTV system does not have to be monitored for OBD II regulations.

Some vehicles may use both systems.

These subsystems are used to provide increased intake airflow to improve torque, emissions and performance. The overall volume of air metered to the engine is controlled by the throttle body. Vehicles equipped with electronic throttle control (ETC) do not use idle air control (IAC).