Intake Air Systems: Overview: Notes
The Intake Air system (Fig 1) 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 which may also be integrated with the MAF sensor. (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.
There are three basic types of intake air sub-systems:
- Intake Manifold Runner Control (IMRC) electric actuated system
- Intake Manifold Swirl Control (IMSC) vacuum actuated system
- Intake Manifold Tuning Valve (IMTV)
These subsystems are used to provide increased intake airflow to improve torque, emissions and performance. The overall quantity of air metered to the engine is controlled by the throttle body.