During a predetermined operation state in which the opening degree of a throttle valve is fixed, an air flow meter positioned more on the upstream side than a pressure control valve detects a first intake air amount when the opening degree of the pressure control valve positioned on the upstream side of the throttle valve is set to a predetermined first valve opening degree and a second intake air amount when the opening degree of the pressure control valve is set to a predetermined second valve opening degree smaller than the first valve opening degree. On the basis of the first intake air amount and the second intake air amount, a diagnosis is made regarding whether there is an abnormality in a first pipe, a second pipe, a third pipe and the like which are included in a blow-by gas recirculation system for blow-by gas treatment.

Methods and systems are provided for a vacuum generating throttle. In one example, a method may include pivoting the throttle based on a desired airflow rate and/or vacuum replenishment, where the airflow rate and/or vacuum replenishment are adjusted based on one or more passages arranged interior to the throttle.

Methods and systems are provided for generating vacuum via a throttle. In one example, a method may comprise rotating the throttle to a first fully closed position to provide vacuum to a first vacuum consumption device and rotating the throttle to a second fully closed position to provide vacuum to a second vacuum consumption device. The method may further include rotating the throttle to a partially closed position to provide vacuum to both the first and second vacuum consumption devices.

Methods and systems are provided for a pressure tapping device for a motor vehicle where a portion of the pressure energy generated at the fuel storage reservoir is transmitted to a working medium, physically separate from the fuel via the pressure tapping device. The pressure tapping device is fluidically coupled to a pressure actuator and enables the pressure operation via transmission of the pressure energy and adjustment of valves diverting flow from the fuel storage reservoir to the engine intake through the pressure tapping device.

Methods and systems are provided for improving the efficiency of canister purge completion. Based on engine operating conditions, a canister is purged to a compressor inlet or a throttle outlet. During purging conditions, as canister loads change, a purge flow through the canister is varied so that a fixed preselected portion of total engine fueling is delivered as fuel vapors.

Methods and arrangements for transitioning an engine between a deceleration cylinder cutoff (DCCO) state and an operational state are described. In one aspect, transitions from DCCO begin with reactivating cylinders to pump air to reduce the pressure in the intake manifold prior to firing any cylinders. In another aspect, transitions from DCCO, involve the use of an air pumping skip fire operational mode. After the manifold pressure has been reduced, the engine may transition to either a cylinder deactivation skip fire operational mode or other appropriate operational mode. In yet another aspect a method of transitioning into DCCO using a skip fire approach is described. In this aspect, the fraction of the working cycles that are fired is gradually reduced to a threshold firing fraction. All of the working chambers are then deactivated after reaching the threshold firing fraction.

Methods and systems are provided for a vacuum generating throttle. In one example, a method may include pivoting the throttle based on a desired airflow rate and/or vacuum replenishment, where the airflow rate and/or vacuum replenishment are adjusted based on one or more passages arranged interior to the throttle.

Methods and systems are provided for a vacuum generating device. In one example, a vacuum generating device comprises a venturi device upstream of an annular fixture for adjusting an amount of vacuum provided to a vacuum consumption device.

Various systems and methods are described for generating vacuum within an engine intake. An intake throttle including a hollow throttle plate having a plurality of perforations along its circumference is mounted on a hollow shaft, which in turn may be coupled to a vacuum consumption device. When vacuum is demanded by the vacuum consumption device, the opening of the throttle plate may be decreased and vacuum may be generated by flowing intake air past the perforated edge of the throttle plate.

A manually adjustable aspirator is disclosed for use in a vacuum system for a vehicle having a vacuum source. The aspirator includes a passageway having a diameter that can be adjusted by a vehicle operator for different altitudes. The aspirator includes a body, a passageway having a narrowed aperture defined by opposed cones, and a manually adjustable flow adjuster having an adjustment knob. A brake booster is connected to the aspirator. An air intake is connected with a vacuum source and the aspirator. The cones include first and second cones each having a narrowed end. The narrowed ends are joined at a narrow aperture that defines an inner diameter. The flow rate adjuster regulates the size of the inner diameter. Adjustment of the knob allows operator selection between a high boost in a high altitude location and a low boost in a low altitude location having a higher source vacuum.