1. On a warm engine idling, create a vacuum of 8 mm. rt. post on the valve fitting. If the idle speed drops by 100 rpm when a vacuum is created, and when the vacuum is removed, the speed is restored, then the valve is working.
Otherwise, check the cleanliness of the valve. If valve cleaning fails, replace the valve.
2. To remove the valve, disconnect the battery from the mass, disconnect the connector and vacuum hose from the valve, disconnect the latches and remove the valve from the intake manifold.
3. Installation is carried out in the reverse order. Replace valve gasket.