The application relates to a method and system for a boosted engine system, and provides methods and systems for operating an electric supercharger as an on-board air pump and/or vacuum pump. During conditions when a vehicle is not being propelled and the vehicle engine is idling, a portion of an air intake passage is sealed and the supercharger is operated to deliver compressed air into the sealed portion. Compressed air can then be picked up directly from the sealed portion for use in tire inflation, or picked up via an ejector to provide vacuum for vacuum actuators.