Function And Operation Principle
Variable Intake manifold Solenoid (VIS) valves are installed on surge tank (VIS Valve #1) and intake manifold (VIS Valve #2). These VIS valve #1 and #2 control vacuum modulators which activate valves in surge tank and intake manifold. These valves are opened or closed by PCM according to engine condition (Refer to below table).
VARIABLE INTAKE SOLENOID VALVE FUNCTION AND OPERATION PRINCIPLE
| Engine Condition | VIS Valve #1 (Surge Tank) | VIS Valve #2 (In-manifold) | Operation |
|---|---|---|---|
| Low Speed | Closed | Closed | Increasing engine performance in low engine speed by reducing intake interference among cylinders |
| Medium Speed | Open | Open or closed | Increasing intake efficiency |
| High Speed | Open | Open | Minimizing intake resistance by shortening intake manifold length and increasing area of air entrance |