A method for safe gas turbine startup is disclosed. The method comprises a first step wherein a fuel metering valve (33) arranged along a fuel delivery line is tested for possible leakages. If the leakage test is successfully passed, a subsequent turbine startup step can be performed. Further disclosed is a gas turbine engine (3) comprising a fuel supply system (20) comprised of a fuel delivery line (21) and a valve arrangement (23) positioned along said fuel delivery line (21). The valve arrangement (23) further comprises sequentially arranged shut off valves (25, 29, 31) and a fuel metering valve (33), positioned downstream of the shut off valves (25, 29, 31). A pressure measuring arrangement (43, 45, 47) is further provided, adapted to measure fuel pressure in at least one portion of the fuel delivery line (21) upstream of the fuel metering valve (33).

Methods and systems are provided for diagnostics of a fuel system configured with a three-way isolation valve and a four port canister. An example method includes, during a refueling event, indicating degradation of the three-way isolation valve based on pressure in the fuel tank during depressurization followed by refueling.

A control system for a vehicle includes a controller. The controller is configured to receive signals from a plurality of vehicle sensors, a vehicle communications system, a ride-share application, a navigation system, or a combination of these. The controller is configured to determine whether at least one of a plurality of conditions is met to execute a small leak test on a fuel system of the vehicle based on the signals, where the plurality of conditions include an available time segment to execute the small leak test, a level surface, a smooth surface, and a constant vehicular momentum. The controller is configured to execute the small leak test when at least one of the plurality of conditions is met.

The present disclosure relates to a method for controlling pressure of an engine, including a controller structured to implement the method and an engine system including the controller. More specifically, the present disclosure relates to a method based on a mass balance analysis of a fuel system to determine how much mass needs to be pumped to maintain or achieve a certain pressure for the engine. In some embodiments, the method analyzes how much mass can be pumped by each pumping event based on current engine conditions. The analysis is performed over the smallest repeatable pump events and cylinder events cycle, or “subcycle,” based on the number of pump events and cylinder events for a given engine configuration.

A method that includes coupling an external, removable fuel pressurization system to a fuel system of a vehicle while the vehicle remains in a confined space. The fuel system of the vehicle is pressurized with the fuel pressurization system while the vehicle remains in the confined space and without activating an engine of the vehicle. Decay of pressure of the fuel system is monitored following pressurization of the fuel system, and one or more of a leak, or a replaceable component, of the fuel system of the vehicle is detected based on at least in part on the decay of pressure that are monitored.

A method and a device detect and characterize fuel leakage in an injection system of an internal combustion. The injection system has an injection device for injecting fuel into a combustion chamber of the internal combustion engine, a closable high-pressure branch for supplying the injection device with fuel placed under a first fuel pressure, and a closable low-pressure branch for feeding fuel placed under a second, lower fuel pressure from a fuel supply to the high-pressure branch. The high-pressure branch and the low-pressure branch are each closed, wherein in the high-branch branch and in the low-pressure branch an associated curve of fuel pressure over time is sensed at the same time during a measurement time period. On the basis of the sensed curve of fuel pressure of the high-pressure branch, it is checked whether fuel loss occurred in the closed-off high-pressure branch during the measurement time period. By way of the sensed curve of fuel pressure of the low-pressure branch, it is checked whether a flow of fuel into the closed-off low-pressure branch occurred during the measurement time period. If the existence of fuel loss was determined in the first checking step and additionally it was determined in the second checking step that no flow of fuel into the low-pressure branch occurred, a signal is output, which indicates fuel leakage from the high-pressure branch into the combustion chamber.

A system and method for leak check module including first and second solenoid valves. A first solenoid valve is configured to be coupled between a fuel vapor canister and atmospheric air for controlling air flow in a first flow path between the fuel vapor canister and atmospheric air. A pump is configured to be coupled to atmospheric air. A second solenoid valve is configured to be coupled between the pump and the fuel vapor canister for controlling air flow in a second flow path between the fuel vapor canister and atmospheric air through the pump.

A dual path fuel vapor purge system is disclosed for an engine having a turbocharger or a super. The purge system includes a canister configured to collect fuel vapor from a fuel tank. A canister purge valve is provided downstream from the canister. An ejector valve receives fuel vapors from the canister through the canister purge valve. A first vapor purge path directs the fuel vapor to an intake manifold of the engine. A second vapor purge path directs fuel vapor to an air induction system. A check valve downstream from the ejector valve receives the fuel vapor from the ejector and supplies the fuel vapor to the air induction system. Boost flow opens the check valve when the air induction system is in operation to boost the engine and closes the check valve when the engine is in operation with normal aspiration or when a leak is detected.

A fuel control system obtains a measured amount of fuel consumed by an engine and one or more corresponding operating parameters of the engine and determines a fuel consumption modeled amount based at least in part on a fuel consumption model of the engine and the one or more operating parameters. The fuel consumption model associates different amounts of fuel that, when supplied to the engine, generate corresponding designated outputs of the engine. The system also determines one or more differentials between the measured amount of fuel and the modeled amount and, responsive to the one or more of the differentials exceeding a threshold value, the system identifies one or more components of the powered system that contribute or cause the one or more differentials and/or changes an amount of fuel supplied to the engine according to the fuel consumption model to obtain a desired output of the engine.

A system for diagnosing a misfire of an engine includes a sensing unit including at least one sensor for detecting at least one detection value associated with an operation of the engine, and an electronic control unit configured to determine whether a misfire of the engine due to exhaust valve leakage has occurred based on the detection values from the sensing unit, and perform an operation corresponding to the misfire due to exhaust valve leakage when the misfire due to exhaust valve leakage has occurred, wherein the electronic control unit a misfire code for exhaust valve leakage in a memory when the misfire due to exhaust valve leakage has occurred.