Variable Induction System: Description and Operation

Swirl Control Valve (SCV) Input And Output Chart:

PURPOSE
The Swirl Control System is a two-stage intake system.
The system allows for a high velocity, low volume intake charge at idle and an unrestricted, high volume charge at higher engine speeds.


LOCATION
The swirl control valving is inside the intake manifold and the controller is mounted to the outside of the manifold.


OPERATION
The Swirl Control Valve has two positions; partially closed or fully open.

The Swirl Control Valve (SCV) partially closes off the intake passage of each cylinder at idle, restricting air flow. This causes the velocity of the intake mixture to increase, promoting better vaporization of the mixture. This increase in velocity makes the fuel mixture burn faster, increasing fuel economy and engine stability.

During all other operating conditions the SCV opens allowing the intake flow to encounter less resistance, improving power and acceleration.

The ECM supplies the ground circuit to the SCV solenoid. When the solenoid is grounded, vacuum is allowed to pass the Swirl Control Actuator and the Swirl Valves are closed. When the solenoid ground is cut, the Swirl Control Actuator vacuum is lost and the Swirl Valves are opened.