Arrangement of elements of the induction air supply system to the engine
The induction air supply system changes the direction of air flow in the intake manifold depending on engine speed.
The system's actuator is controlled by vacuum created in the intake manifold.
1. To test the induction air supply system, install a tee with a pressure gauge between the control valve and the vacuum hose.
2. Run the engine at idle speed. The pressure gauge should not show vacuum.
3. Briefly press the accelerator pedal all the way down. The pressure gauge should show a vacuum and the actuator rod should move.
4. If there is no vacuum, check the vacuum hose for leaks and the vacuum changeover valve (VSV) for proper operation.
5. Check the condition of the vacuum tank by blowing air through it. When air is supplied to channel A, air should come out of channel B, and no air should pass in the opposite direction.
6. While creating a vacuum in the vacuum reservoir through channel B, use your finger to check that the vacuum in channel A is maintained for at least 1 minute.
7. To check the vacuum switching valve, connect an ohmmeter to its contacts and measure the resistance, which should be within 33–39 ohms.