Methods and systems are provided for determining an extent of clogging of a canister filter included in a fuel vapor storage canister of a vehicle. In one example, a method comprises determining an extent to which the canister filter is clogged based on an output of an exhaust gas sensor, and adjusting one or more parameters related to purging of the fuel vapor storage canister as a function of the extent to which the canister filter is clogged. In this way, canister lifetime may be improved, and release of undesired evaporative emissions to atmosphere may be reduced or avoided.

A method for detection of a fuel line leak in a fuel system that includes a fuel reservoir, a generator and a fuel line. The method includes providing a pressure vessel. The method further includes connecting a test valve to the fuel line. The valve has a test position and a non-test position. In the test position the valve allows fluid communication between the fuel line and the pressure vessel, and in the non-test position the valve does not allow passage. The method includes monitoring a status of the generator and detecting the status of the generator to be idle. The method includes moving the valve to the test position and moving the valve to the non-test position upon detection of the status of the generator to be active. The method includes pressurizing the pressure vessel and the fuel line. The method includes measuring the pressure in the pressure vessel.

A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.

A pressure-regulating device for a fuel consumption measurement system includes a fuel supply line which supplies fuel to a consumer, a fuel return line, a bypass line which branches off from the fuel supply line, a pressure regulator which sets a free flow cross-section in the bypass line, a pressure sensor arranged at the fuel supply line downstream of where the bypass line branches off, a control unit electrically connected to the pressure sensor, and a pressure-reducing element arranged in the fuel supply line upstream of the pressure sensor and downstream of the branch of the bypass line. The bypass line fluidically connects the fuel supply line to the fuel return line and feeds fuel from the fuel supply line to the fuel return line while bypassing the consumer. The pressure sensor provides pressure measurement values. The control unit regulates the pressure regulator depending on the pressure measurement values.

The invention determines at least one combustion property of a two-phase fuel gas. The invention comprises providing the fuel gas from substantially only a first phase of the fuel gas to a combustion engine and operating the combustion engine such that a first -value is achieved in the combustion process. The invention further provides the fuel gas from substantially only a second of the two phases of the fuel gas to the combustion engine, wherein the second phase is different from the first phase and wherein the same volumetric air/fuel ratio is kept as when the combustion engine was operated with the first -value. The invention determines a second -value when the combustion engine is operated with the fuel gas from substantially only the second of the two phases of the fuel gas and determines at least one first combustion property of the fuel gas based on the second -value.

A movable electrical generation system includes a generator operable to produce a supply of electrical energy, a prime mover operable to drive the generator, a first fuel, a second fuel different from the first fuel, and a fuel selector valve assembly operable to selectively deliver the first fuel and the second fuel to the prime mover, wherein in response to a transition from delivery of the first fuel to the prime mover to delivery of the second fuel to the prime mover, both the first and second fuels are delivered to the prime mover before cessation of delivery of the first fuel.

An outboard motor includes a vapor separator tank, a downstream fuel supply path, a fuel pump that discharges a fuel in the vapor separator tank into the downstream fuel supply path, a downstream bypass path, and a downstream relief valve provided in the downstream bypass path. A first end of the downstream bypass path is connected to a downstream portion that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path, and a second end of the downstream bypass path is connected to an upstream portion between the downstream check valve and the vapor separator tank in the downstream fuel supply path. The downstream relief valve opens the downstream bypass path when a fuel pressure in a downstream region that is closer to the fuel injector than is the downstream check valve in the downstream fuel supply path exceeds a first predetermined value.

A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.

An engine-driven welding generator that monitors fuel level is provided. The engine-driven welding generator comprises a fuel level monitoring system configured to measure a remaining fuel level in a fuel tank of the engine-driven welding generator, determine a rate of fuel usage of an engine of the engine-driven welding generator, and calculate a remaining run time of the engine based on the remaining fuel level and the rate of fuel usage of the engine

An engine-driven welding generator that monitors fuel level is provided. The engine-driven welding generator comprises a fuel level monitoring system configured to measure a remaining fuel level in a fuel tank of the engine-driven welding generator, determine a rate of fuel usage of an engine of the engine-driven welding generator, and calculate a remaining run time of the engine based on the remaining fuel level and the rate of fuel usage of the engine.