A method for identifying a source of high pressure leakage of a fuel system of an engine comprising determining pressure decay values at a first pressure and at a second pressure and identifying the source of high pressure leakage based on the pressure decay values at each pressure.

A failure detection apparatus for fuel systems of an engine includes a first failure determiner executing, while the engine is in each of a first injection form and a second injection form, a failure determination process on the corresponding fuel system, a second failure determiner executing, when the first failure determiner determines occurrence of a failure in one of the injection forms, a failure determination process on the fuel system corresponding to the other injection form, a failure locator determining whether or not the failure has occurred, for each of the fuel systems responsible for the first and second injection forms, based on a result by the second failure determiner, and a purge process prohibiter prohibiting execution of a purge process for the engine. The second failure determiner causes the purge process prohibiter to prohibit execution of the purge process, when executing the failure determination process on the fuel system.

An electrically driven solenoid coupled to a spring-operated valve, regulates pressure in an accumulator by opening when a predefined threshold pressure in a pressure accumulator is exceeded. The solenoid provides an assistive force to a spring-closed valve, reducing the amount of pressure required to open the valve responsive to the amount of current provided to the solenoid. The threshold pressure at which the valve opens is thus determined by the amount of current provided to the solenoid. Increasing the current decreases the threshold pressure; decreasing the current increases the threshold pressure.

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.

An example system includes a controller configured to: receive pressure information indicative of a pressure level of the pressurized fuel between an electro-mechanical valve and an engine; based on the pressure level being below a first threshold pressure, send a first signal to open the electro-mechanical valve; determine, based on the pressure information, that the pressure level is increasing upon sending the first signal; in response to the pressure level increasing, send a second signal to activate a pump; determine that the pressure level has increased to a second threshold pressure; and provide information indicating that the engine is ready for operation.

An apparatus is provided to test valves. The apparatus includes an actuation mechanism having an actuator that seals a valve of a combustion chamber of an engine. The apparatus further includes a flow control device that controls a flow of a pressurized fluid to the combustion chamber. The apparatus further includes a plurality of sensors having a first sensor and a second sensor. The first sensor is disposed in an inlet port of the combustion chamber to detect a first flow rate of the pressurized fluid in the inlet port. The second sensor is disposed in an exhaust port of the combustion chamber to detect a second flow rate of the pressurized fluid in the exhaust port. The apparatus further includes a notification device configured to generate an alert based on the detected first flow rate and the detected second flow rate.

A controller controls a valve device for opening and closing of a passage to control a flow of evaporative fuel evaporating and flowing from a fuel tank. The valve device includes a valve body housed in the passage to open and close the passage, a biasing member biasing the valve body to close the passage, and a driver driving the valve body to open the fuel passage. The controller includes a detector detecting load of the driver and a determiner to determine the position of the valve body. The determiner determines that the passage is open when a magnitude of the change of the driver load is equal to or greater than a threshold value. The controller accurately detects an open valve position without detecting an internal pressure change of the fuel tank.

The present disclosure relates generally to a method for determining a failure of a flow divider within a fuel system, the method being performed by a controller and comprising the steps of: delivering a fuel command, calculating an expected fill time, wherein the expected fill time is indicative of the time required to fill a known fuel manifold volume, determining whether the actual fill time is greater than or equal to an expected fill time; and determining whether an actual fuel pressure value is less than or equal to an expect fuel pressure value based at least in part on at least one environmental signal.

A vehicular liquid containment system including a tank, a pressure sensor arranged to detect a pressure in a vapor dome inside the tank, at least two thermistors configured to detect temperatures at a plurality of levels of the tank, and leak detection logic operatively connected to the pressure sensor and the thermistors. The leak detection logic is configured to: use a first thermistor of the thermistors to perform a first measurement indicative of a temperature in the vapor dome in the tank; estimate an expected pressure evolution in function of at least the first temperature measurement; monitor pressure sensed by the pressure sensor, determine whether the monitored pressure deviates from the expected pressure evolution, and generate a leak condition signal conditional on the determining.

An vapor purge system for a turbocharged internal combustion engine having an evaporative emissions turbo purge valve incorporating a venturi vacuum generator and a hose-off detection function. The turbo purge valve includes a pressure sensor, and a low restriction check valve which is integrated into the outlet port of the venturi vacuum generator. The pressure sensor is capable of detecting the small pressure drop (i.e., vacuum) generated at the air inlet tube or air box during naturally aspirated conditions. The check valve closes the venturi vacuum generator on the purge side during naturally aspirated conditions, allowing fluid communication to the air intake system through one port only, and the detection of the vacuum during these conditions. If a hose becomes detached, either at the outlet port of the venturi vacuum generator or at the air box, the small vacuum is not detected, and the ECU then diagnoses the hose-off condition.