A system for an engine is provided, the system comprising a vacuum pump at least partially deposed within an engine crankcase, and a fuel vapor canister coupled to an exhaust conduit of the vacuum pump via a one-way valve. By coupling the vacuum pump exhaust to the fuel vapor canister, unmetered fuel vapor flow to the engine intake may be reduced, thus decreasing engine stall events. Further, crankcase pressure may more accurately represent airflow through the crankcase via a crankcase ventilation system, thereby improving the accuracy of crankcase ventilation diagnostics.

An engine system including a first flowpath between a first component and a second component where a first aspirator forms a portion of the first flowpath, and a second flowpath between the first component and the second component, where a second aspirator forms a portion of the second flowpath. A shut-off valve forms a portion of the second flowpath. The first aspirator and the second aspirator each have a suction inlet, and the suction inlet of the first aspirator is in fluid communication with the suction inlet of the second aspirator.

An engine system including a first flowpath between a first component and a second component where a first aspirator forms a portion of the first flowpath, and a second flowpath between the first component and the second component, where a second aspirator forms a portion of the second flowpath. A shut-off valve forms a portion of the second flowpath. The first aspirator and the second aspirator each have a suction inlet, and the suction inlet of the first aspirator is in fluid communication with the suction inlet of the second aspirator.

A negative pressure detection part detects a negative pressure from a signal of a negative pressure sensor detecting a negative pressure generated due to rotation of an internal combustion engine. The negative pressure is used to assist a vehicle driver's braking operation. An abnormality determination part determines, during continuation of the internal combustion engine stopped state, that the negative pressure sensor is in an abnormal condition if the detected negative pressure is out of a normal range near an atmospheric pressure to a vacuum pressure side when an operation of decreasing the negative pressure is performed on a brake pedal greater than or equal to a predetermined number of times or greater than or equal to a predetermined period of time or when a total operation amount of the decreasing operation is greater than or equal to a predetermined amount.

A negative pressure detection part detects a negative pressure from a signal of a negative pressure sensor detecting a negative pressure generated due to rotation of an internal combustion engine. The negative pressure is used to assist a vehicle driver's braking operation. An abnormality determination part determines, during continuation of the internal combustion engine stopped state, that the negative pressure sensor is in an abnormal condition if the detected negative pressure is out of a normal range near an atmospheric pressure to a vacuum pressure side when an operation of decreasing the negative pressure is performed on a brake pedal greater than or equal to a predetermined number of times or greater than or equal to a predetermined period of time or when a total operation amount of the decreasing operation is greater than or equal to a predetermined amount.

Methods and systems are provided for providing vacuum to a brake booster via an aspirator system. In one example, a system may include an aspirator system fluidly coupled with a brake booster with no intervening components located therebetween.

Methods and systems are provided for providing vacuum to a brake booster via an aspirator system. In one example, a system may include an aspirator system fluidly coupled with a brake booster with no intervening components located therebetween.

An aspirator for a brake system is provided having the integrated functions of a flow bypass and a check valve for automotive applications to achieve various suction flow openings in response to different engine operating condition to enhance brake boost performance. The brake system includes a brake vacuum booster, an engine having an intake manifold, an aspirator having a movable total flow divergence nozzle, the aspirator being connected to the manifold, and a vacuum line connecting the booster to the aspirator. The aspirator includes a body having an internal end wall. A biasing element such as a spring is provided between the movable total flow divergence nozzle and the internal end wall of the aspirator body. The body of the aspirator includes an air flow path having an upstream area and a downstream area. The movable motive flow nozzle is positioned in the downstream area of the flow path.

A control device calculates an estimate of negative intake pressure based on the relationship between the rotation speed of a crankshaft and a throttle opening degree (Step S24). Then, the control device sets the estimate PE of the negative intake pressure, which is calculated in Step S24, to a greater value as combustion efficiency of CNG used in engine operation becomes higher (Step S25). When the corrected estimate PE of the negative intake pressure becomes smaller than or equal to a reference value PTh (Step S26: YES), the control device starts a negative pressure recovery procedure (Step S27).

A turbocharged engine air system is disclosed. The engine air system includes at least two devices requiring vacuum, a turbocharger having a compressor fluidly connected to an intake manifold of an engine, a first evacuator and a second evacuator. The first evacuator defines a first motive section, a first discharge section, and at least two first suction ports. The first motive section of the first evacuator is fluidly connected to the compressor, and each of the at least two first suction ports are fluidly connected to one of the at least two devices requiring vacuum. The second evacuator defines a second motive section, a second discharge section, and at least two second suction ports. The second motive section of the second evacuator is fluidly connected to at least one of the at least two devices requiring vacuum.