A structure of an intake manifold (1) for an engine is constituted of divided pieces (10, 20, 30). The structure of the intake manifold includes a gas supply hole (53) formed in a predetermined position of an outer surface of the intake manifold, and configured to supply predetermined gas from the outside, and a gas inlet passage (51) formed in predetermined joint surfaces (10m, 20m) of the divided pieces (10, 20), and configured to guide the gas supplied through the gas supply hole to a predetermined gas inlet position (11) of an intake passage (E1).

A fuel tank system includes a fuel storage unit, a processing unit, and a control unit. The control unit performs a first failure diagnosis of diagnosing a failure of the fuel storage unit in a state where the sealing valve is closed. When the control unit diagnoses that the fuel storage unit is normal, the control unit performs a second failure diagnosis of diagnosing a failure of a purge valve and a bypass valve by causing a pressure generation unit to generate pressure in a state where the sealing valve is closed. When there is a possibility that the purge valve and the bypass valve are in closed-sticking, the control unit performs a third failure diagnosis of specifying a failure in any one of closed-sticking of the purge valve and closed-sticking of the bypass valve by opening the sealing valve.

A method is presented, comprising, during a first condition, including an active refueling event, receiving an indication of hydrocarbon breakthrough from the fuel vapor canister; and flowing refueling vapors into an intake manifold responsive to the indication of hydrocarbon breakthrough. Flowing refueling vapors into an intake manifold traps the vapors there until engine start-up, when the vapor can be combusted by the engine. In this way, refueling emissions may be reduced, even if the fuel vapor canister is saturated prior to, or during the refueling event.

A method, comprising indicating an amount of a residual fuel in a fuel tank based on an initial rate of change of a fuel tank pressure during a refueling event. The initial rate of change of fuel tank pressure is proportionate to the amount of vapor dome space within the fuel tank, and thus proportionate to the amount of residual fuel left in the fuel tank. In this way, the fuel tank fill level may be accurately quantified, even during cases where the fill level indicator experiences degradation.

A system according to the present disclosure includes a pump operating parameter module and a purge flow control module. The pump operating parameter module determines a value of an operating parameter of a purge pump that delivers purge fluid from a canister in an evaporative emissions system to an intake system of an engine. The operating parameter of the purge pump includes at least one of a speed of the purge pump, an amount of current supplied to the purge pump, and an amount of power supplied to the purge pump. The purge flow control module controls at least one of a purge valve and the purge pump to adjust an amount of purge fluid delivered to a cylinder of an engine based on the determined value of the operating parameter of the purge pump.

A fuel vapor processing apparatus may include a canister. A negative pressure applying device for applying a negative pressure to the canister may be disposed in a purge passage communicating between the canister and an intake pipe of an engine. A pressure adjusting device may be disposed in a portion of the purge passage communicating between the fuel tank and the negative pressure applying device.

Methods and systems are provided for detecting a fuel tank oil-canning event during conditions when a vacuum is applied to the fuel tank, such as during a fuel system leak test or during purging of a fuel system canister. In one example, a method may include comparing the fuel tank pressure changes during a leak test to changes in fuel tank temperature or fill level and indicating fuel tank oil-canning in response to a higher than threshold rise in fuel tank pressure during or following application of vacuum to the fuel tank while each of a fuel temperature and fill level remain unchanged. By detecting fuel tank oil-canning accurately, appropriate countermeasures can be taken.

A fuel vapor processing apparatus includes a canister housing an adsorbent material that adsorbs fuel vapor from a tank, and a valve in a passage connecting the canister and tank. When a stroke amount is within a range, the valve is closed to close the tank and a valve opening start position is learned. In the learning, the stroke amount is varied in the opening direction by repeatedly changing in the opening direction by a first stroke and maintaining for a first time period, and subsequently changing in a closing direction by a second stroke and maintaining for a second time period. The valve opening start position is determined based on the stroke amount in the second time period when the tank pressure is reduced by the predetermined value or more or in a preceding process.

A purge control solenoid valve includes a gas access body including an evaporation gas inlet, an evaporation gas outlet, and a path that connects the evaporation gas inlet and the evaporation gas outlet; a valve operation body including an armature coupled to the gas access body and performing a reciprocating motion in a direction in which the armature is brought into close contact with or separated from the path by a core that generates a magnetic force; and an armature top member being in close contact with or separated from the path due to the reciprocating motion of the armature to open or close the path. The armature top member has a non-adhesion coating formed on a top surface of a body thereof, and the non-adhesion coating includes a binder, graphite, polytetrafluoroethylene, and a crosslinking agent.

An evaporation fuel purge system includes: a fuel tank; a canister that absorbs and desorbs evaporation fuel emitted from the fuel tank; an intake passage for an internal combustion engine in which the evaporation fuel desorbed from the canister is mixed with fuel for combustion; a purge passage that connects the canister to the intake passage; an ejector device disposed in the purge passage; and a fluid drive device. The ejector device has a nozzle part that accelerates external fluid. The fluid drive device sends outside air corresponding to the external fluid to flow into the nozzle part.