In some embodiments, content is generated that includes a street map, at least one path on the map indicating a route of travel by a mobile gas measurement device, and at least one indicator on the map that indicates a survey area for a potential gas leak source. The survey area adjoins the path and extends in a substantially upwind direction from the path. The survey area has a boundary determined such that if the potential gas leak source is located in the survey area and has a rate of leakage meeting a minimum leak rate condition, then an estimated probability of detection of a gas leak from the potential source at one or more measurement points along the path satisfies a probability condition.

Methods and systems are provided for diagnosing fuel vapor leaks due to un-latching of quick connectors in interfaces of a fuel vapor system. In one example, a method may include using positive pressure generated in the intake manifold by reverse rotation of the engine unfueled, to detect un-latching of quick connectors in the fuel vapor system. After the positive pressure test, a negative pressure test is performed on the fuel vapor system to confirm any un-latching of quick connectors.

Various systems are provided for delivering fuel to an engine. In one example, a system includes a controller and a fluid system configured to maintain a fluid at a pressure downstream of a check valve. The controller may be configured to determine if a leak is present in the fluid system based on a first pressure decay rate of the fluid system, and responsive to identifying that a leak is present in the fluid system, differentiate between an internal leak and an external leak based on a leak flow rate as fluid system pressure decreases.

Solid storage media stores a reductant in a reductant source that is released from the solid storage media in a gaseous form into an exhaust system. A leak detection and/or leak mitigation system, method and apparatus is disclosed for the gaseous reductant.

In some embodiments, a computer system generates display content indicating a likely direction and estimated distance to a potential gas leak source. The content includes a street map and at least one search area indicator on the map that indicates a search area suspected to have a gas leak source. The search area indicator has an axis indicating a representative wind direction relative to a geo-referenced location of at least one gas concentration measurement point. The search area indicator also has a width relative to the axis. The width is indicative of a wind direction variability associated with a plurality of wind direction measurements in an area of the gas concentration measurement point. The axis also preferably has a length indicating an estimated maximum distance to the potential gas leak source.

A method of diagnosing a fault in a common rail fuel system having a proportional-integral-derivative (PID) controller includes determining a first integral output corresponding to a first fuel flow condition and a first rail pressure setting. The method includes comparing the first integral output with a threshold integral output and determining a second integral output corresponding to a second fuel flow condition and the first rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes determining a third integral output corresponding to the first fuel flow condition and a second rail pressure setting, when the first integral output is greater than the threshold integral output. The method includes identifying a failure in at least one of a flow control valve arrangement and a pressure relief valve of the common rail fuel system based on the first, second, and the third integral outputs.

A method for determining a leakage of fuel in a high-pressure region of a fuel supply system for an internal combustion engine of a vehicle. A curve of a pressure in a high-pressure accumulator of the fuel supply system is provided. A value for a pressure drop is determined in each of one or more segments of the curve, wherein in one segment or in each of the plurality of segments the vehicle is in overrun, no fuel is injected into the internal combustion engine, and no fuel is pumped into the high-pressure accumulator. Information about the leakage is determined on the basis of the one or more values.

A first pressure sensor is disposed in a first fuel system between a first shutoff valve and a second shutoff valve. A second pressure sensor is disposed in a second fuel system between the second shutoff valve and a fuel injection valve. A determination process determines a leakage anomaly in the first fuel system or the second fuel system based on a first magnitude relationship or a second magnitude relationship. The first magnitude relationship is a relationship between a detection value of the first pressure sensor in a state in which the first fuel system is filled with gaseous fuel and a first threshold value. The second magnitude relationship is a relationship between a detection value of the second pressure sensor in a state in which the second fuel system is filled with gaseous fuel and a second threshold value.

A fuel injector adapter for an internal combustion engine, including an adapter shaft including a first shaft end disposed within a fuel injector, a second shaft end, a shaft passage disposed in the adapter shaft extending from the first shaft end to a port portion of the adapter shaft, the port portion including annular openings; and an adapter body disposed over the adapter shaft, including a fitting portion including a first end, a second end, and a bore including a fuel portion, an elbow port spaced from the fitting portion, the elbow port including a port fuel portion, and an extension connecting the fitting portion to the elbow port, the extension including a fuel passage for connecting the port fuel portion of the elbow port to the fuel portion of the bore proximate the annular openings of the port portion of the adapter shaft.

A fuel leak diagnostic system includes: a high-pressure pump configured to pressurize liquid fuel supplied from a fuel tank; a pressure accumulator configured to store the liquid fuel discharged from the high-pressure pump; an in-cylinder injection valve configured to inject the liquid fuel in the pressure accumulator directly into a cylinder of an engine; and a diagnostic device configured to diagnose a leak of the liquid fuel from the in-cylinder injection valve.