Variable Induction Control Valve: Testing and Inspection

Central MFI Air Flow Diagram:

The diagnosis of the tuning valve circuit can be found in System Diagnosis/Procedures.

The tuning valve (rotary solenoid device) is electrically controlled by the control module based on RPM and Throttle Position (TP) signal inputs, for accurate switching capability at optimum switching points to enable either a "split" or "single" plenum condition.

During the low and high end of the RPM range, the control module de-energizes the valve and enables a "split" plenum condition that provides for peak torque along with increased peak horsepower.

During the mid RPM range, the control module energizes the valve, thus enabling a "single" tuning plenum condition that provides for mid RPM range peak torque.