Methods and systems are provided for conducting a diagnostic on a fuel tank isolation valve that regulates a flow of fuel vapors from a fuel tank to an evaporative emissions system. In one example, a method comprises determining whether the fuel tank isolation valve is stuck in a first open position or a second open position based on a time duration between commanding open a canister purge valve to direct fuel vapors to an engine, and an exhaust gas sensor indicating a rich air-fuel ratio. In this way, appropriate mitigating action may be taken in response to the fuel tank isolation valve being stuck in either the first open position or the second open position.

In at least some implementations, a system includes a pump having an electric motor and a pump outlet, a controller coupled to the pump to vary the power provided to the motor to vary the flow rate of liquid discharged from the pump outlet, a pressure regulator having an inlet communicated with the pump outlet, a regulator outlet from which liquid is discharged from the regulator, a bypass outlet through which liquid is discharged from the regulator, and a pressure responsive valve that opens to permit liquid flow through the bypass outlet, and a flow sensor. The flow sensor is communicated with the bypass outlet to sense or determine a flow rate of liquid at or downstream of the bypass outlet, the flow sensor also communicated with the controller to provide an indication of the bypassed liquid flow rate to the controller.

A system for protecting a high-pressure accumulator fuel injection system of an internal combustion engine against excessively high fuel pressures occurring in a high-pressure accumulator of the fuel injection system caused by a malfunction in the fuel injection, wherein the system comprises a member measuring the fuel pressure inside the high-pressure accumulator and sending information about this pressure to a control unit. An electrically controllable inlet valve to a pumping element of a high-pressure pump is included in the system and controlled by the control unit to be transferred to a continuously open or closed state, if the pressure measured exceeds a predetermined pressure level for stopping the feeding of fuel by the pumping element to the high-pressure accumulator.

A method for operating a speed-controlled fluid pump includes: providing an electrical control current for the fluid pump; providing a maximum value for the electrical control current, which maximum value corresponds to a maximum permissible pressure at an outlet side of the fluid pump; providing a threshold value for the control current, the threshold value corresponding to a further maximum permissible pressure at the outlet side of the fluid pump and is predefined in dependence upon at least one boundary condition, the threshold value being less than the maximum value for the electrical control current; and controlling the fluid pump with not more than the threshold value for the control current, if it has been determined that the at least one boundary condition holds, so as to limit the pressure at the outlet side of the fluid pump to a value provided for the at least one boundary condition.

Systems are disclosed for supplying fuel to fuel-injected gensets in a recreational vehicle. An apparatus includes a fuel injection system having a fuel reservoir and a first pump fluidly coupled to the first reservoir and structured to supply fuel to the fuel reservoir. The fuel injection system is further provided with a pressure sensor and a second pump. The second pump is fluidly coupled to the pressure sensor and structured to provide pressurized fuel from the fuel reservoir to one or more fuel injectors of an associated engine. The second pump is a variable speed fuel pump.

Methods and systems are provided for conducting a diagnostic on a fuel tank isolation valve that regulates a flow of fuel vapors from a fuel tank to an evaporative emissions system. In one example, a method comprises determining whether the fuel tank isolation valve is stuck in a first open position or a second open position based on a time duration between commanding open a canister purge valve to direct fuel vapors to an engine, and an exhaust gas sensor indicating a rich air-fuel ratio. In this way, appropriate mitigating action may be taken in response to the fuel tank isolation valve being stuck in either the first open position or the second open position.

There are provided an intake pressure detecting means for detecting an intake pressure on more downstream side than a throttle valve in an intake passage to an engine, a rotational speed detecting means for detecting a rotational speed of an engine, an engine controlling means for controlling the engine to arrive at a target air-fuel ratio corresponding to the detected intake pressure and the detected engine rotational speed and an abnormality treating means for executing an engine stopping treatment to stop the engine if an intake pressure higher than a set pressure has been detected and an engine rotational speed higher than a set rotational speed has been detected, when an opening degree state detecting means detects that the throttle valve is under a fully closed or substantially fully closed state.

A vehicular propulsion system, a vehicular fuel system and a method of operating an internal combustion engine. A separation unit that makes up a part of the fuel system may selectively receive and separate at least a portion of onboard fuel and a flowable adsorbent in order to separate the fuel into octane-enhanced and cetane-enhanced fuel components. A controller may be used to determine a particular operating condition of the internal combustion engine such that the onboard fuel can be sent to one or more combustion chambers within the internal combustion engine without first passing through the separation unit during one operating condition, or instead to the separation unit in situations where the internal combustion engine may require an octane-rich or cetane-rich mixture in another operating condition.

A primary metal terminal connects between a fuel pump and a drive circuit through a resin lid. A primary connecting point of the primary metal terminal connected to the drive circuit, is positioned around a drive control IC, and a primary exposed portion of the primary metal terminal, exposed to a receiving space of the resin lid is bent such that the primary exposed portion is resiliently deformable. A secondary metal terminal connects between an external circuit system and the drive circuit through the resin lid. A secondary connecting point of the secondary metal terminal connected to the drive circuit is positioned at a location that is further spaced from the drive control IC in comparison to the primary connecting point, and a secondary exposed portion of the secondary metal terminal exposed to the receiving space has a stiffness higher than a stiffness of the primary exposed portion.

A method for checking a measurement of pressure in a fuel tank, implemented in a vehicle having a fuel tank and a fuel vapor breather circuit including: a filter, a tank isolation valve interposed between the tank and the filter, and a purge line, connected to the filter, downstream thereof, a pressure sensor, and a purge valve. The method includes, when the purge valve is closed: measuring a value of the pressure in the tank when the isolation valve is closed, then measuring a temporal extreme value for the pressure in the purge line following an opening of the isolation valve, and determining, from the measured values, that there is an anomaly in the measured pressure in the tank.