Abstract: A system comprises an engine including a plurality of cylinders. A first intake throttle is positioned upstream of a first set of cylinders of the plurality of cylinders. The first intake throttle provides air at a first flow rate to the first set of cylinders so as to produce a lean air/fuel mixture in the first set of cylinders. A second intake throttle is positioned upstream of a second set of cylinders included in the plurality of cylinders and in parallel of the first intake throttle. The second intake throttle provides air at a second flow rate to the second set of cylinders so as to produce a rich air/fuel mixture in the second set of cylinders.

Abstract: A method to process exhaust gas expelled from at least one cylinder of a plurality of cylinders of an internal combustion engine, the method comprising providing an internal combustion engine, wherein the engine comprises a steam hydrocarbon reformer including a steam reformation catalyst, treating exhaust gas of the engine containing hydrocarbon and water by reacting the hydrocarbon and water in the presence of the steam reformation catalyst in the steam hydrocarbon reformer to provide treated exhaust gas. The treated exhaust gas includes carbon monoxide gas and hydrogen gas produced from the reaction, and mixing the treated exhaust gas, including the carbon monoxide gas and hydrogen gas produced in the steam hydrocarbon reformer with air to provide the mixture of air and treated exhaust gas introduced into the cylinders of the engine.

Abstract: A device includes at least one ammonia storage cartridge comprising an outlet orifice for ammonia intended to be connected to an ammonia transport circuit towards an exhaust line. The device includes an obturator to obturate the outlet orifice, and which is capable of changing between an obturation configuration of the outlet orifice and a configuration for clearance the outlet orifice. The device includes a detector to detect at least one predefined situation, and a controller to control the obturator, and which is capable of controlling the transition of the obturators towards their obturation configuration when the detector detects the predefined situation.

Abstract: An engine control system includes a selective catalyst reduction (SCR) device that reduces nitrogen oxide (NOx) in exhaust gas in the presence of the reductant. A particulate filter (PF) is disposed downstream from the SCR device to collect particulate matter from the exhaust gas stream. The engine control system further includes an electronic hardware that calculates a particulate matter load value indicating an amount of particulate matter collected in the PF, and calculate a CCB value that compensates for pressure differential variations across the PF. The controller further calculates a CCB correction value that modifies the CCB value and compensates for an amount of reductant that slips from the SCR device and induces the pressure differential variations. In this manner, the electronic hardware controller can control a regeneration system to increase the temperature of the PF to burn off particulate matter from the PF based on the modified CCB value.

Abstract: In a method for diagnosing an SCR catalyst system of an internal combustion engine, the SCR catalyst system comprises at least one first SCR catalyst device (20) and at least one second SCR catalyst device (30). A first injection position upstream of the first SCR catalyst device (20) in the form of a first metering device (40) is provided for injecting liquid reducing agent for the SCR catalyst devices (20, 30). A second injection position between the two SCR catalyst devices (20, 30) in the form of a second metering device (50) is furthermore provided. Both SCR catalyst devices (20, 30) are monitored in a differentiated way by means of active and passive diagnostic methods.

Abstract: In order to surely remove deposits attached on the inner wall of an exhaust gas pipe, an exhaust gas measurement system that measures components contained in the exhaust gas of an internal combustion engine is adapted to include an exhaust gas piping member into which the exhaust gas is introduced; a purge gas supply mechanism adapted to supply purge gas to the exhaust gas piping member; a heating mechanism adapted to heat the exhaust gas piping member; and a control mechanism adapted to, after the heating mechanism has heated the exhaust gas piping member or the exhaust gas flowing through the exhaust gas piping member to a predetermined temperature, control the purge gas supply mechanism to start supplying the purge gas.

Abstract: A component of an exhaust system for a combustion engine has a wall in which at least one opening is provided, and a perforated cover which is associated with the opening. A support is provided by which the perforated cover is mounted to the wall of the component. Further, a clearance is provided between the support and the cover such that the cover can shift parallel to the wall of the component.

Abstract: A muffler includes an elongated muffler shell body with a first muffler end cap mounted on the first end of the muffler shell body in a manner defining a first muffler joint and a second muffler end cap mounted on the second end of the muffler shell body in a manner defining a second muffler joint. A louver and baffle assembly is mounted within an interior of the muffler shell body. The first end of the muffler shell body includes a first shell bead/ridge and the second end of the muffler shell body includes a second shell bead/ridge, and each of the circumferential edges of the first muffler end cap and the second muffler end cap are formed to define cap bead/ridges shaped and dimensioned for engagement with the first shell bead/ridge of the first end of the muffler shell body and the second shell bead/ridge of the second end of the muffler shell body.

Abstract: A body of an oil jet is provided with: an oil supply port; a cylinder; and an oil injection port. A piston valve is accommodated in the cylinder. The piston valve forms in the cylinder a differential pressure room which is a closed compartment. In the piston valve, an orifice which makes the differential pressure room being communicated with a side of the oil supply port is formed. The piston valve is biased toward a position at which the oil injection port is closed by a spring. A first oil injection nozzle is connected to the oil injection port. A leak hole which allows oil to be leaked outside of the cylinder from the differential pressure room is open at the side surface of the cylinder. Further, a second oil injection nozzle is connected to the leak hole.

Abstract: Methods and systems are provided for controlling exhaust flow and recovering heat from exhaust gas under different operating conditions. In one example, motive flow of fresh air via an ejector coupled to an exhaust bypass assembly may be utilized to divert exhaust through a heat exchanger during cold-start conditions and heat extracted from the exhaust gas may be utilized for passenger cabin heating and other vehicle heating demands. The exhaust bypass assembly may also be used for EGR delivery wherein the exhaust heat exchanger may be used as an EGR cooler.

Abstract: A marine propulsion device includes an internal combustion engine; an axially elongated exhaust conduit that conveys exhaust gas from the upstream internal combustion engine to a downstream outlet; a cooling water sprayer that is configured to spray a flow of cooling water radially outwardly toward an inner diameter of the axially elongated exhaust conduit; a temperature sensor located downstream of the cooling water sprayer and configured to sense temperature of the exhaust gas and cooling water; and a controller configured to identify a fault condition associated with the cooling water sprayer based on the temperature of the exhaust gas and cooling water.

Abstract: A system comprises a compartment, a fan, and a dual-pivot hinge. The compartment comprises an interior region and an access opening in communication with the interior region. The dual-pivot hinge mounts the fan to the compartment.

Abstract: In a water-cooled inner combustion engine (1), in particular for equipping scooters and motorcycles, the arrangement of the outer cooling tubes connected to a radiator is simplified by arranging a by-pass valve (27), arranged directly on the engine block (2) at a discharge opening (18) obtained therein, which, when the cooling water is lower than a reference temperature, prevents the water circulation in the radiator (18) and it addresses it through a by-pass line (26) by implementing a cooling circuit wholly included in the engine block (2).

Abstract: An apparatus and method for monitoring the state of opening of a control valve of a coolant circuit of a combustion engine. There is disclosed a method of a control valve of a coolant circuit of a combustion engine, with the control valve having a valve element that is actuatable by an actuator for enabling and/or blocking a coolant flow in the coolant circuit which has a heat exchanger, and having an assembly for detecting the position of the valve element for monitoring the opening state of the control valve. There also is provided an apparatus for carrying out the method.

Abstract: An expansion tank, while maintaining gas-liquid separation performance of coolant circulating through an engine cooling apparatus, can absorb pressure variations occurring with volume change of the coolant even when an excessive amount of coolant is supplied. A bulkhead 42 partitions an expansion tank 30 into separate chambers R1 to R6 that communicate with each other via a first communication hole 44 positioned lower than a FULL line. The separate chambers R4 to R6 that constitute a separate chamber group X communicate with each other via a third communication hole 45a positioned higher than the FULL line. The separate chambers R1 to R3 that constitute a separate chamber group Y communicate with each other via a fourth communication hole 45b positioned higher than the FULL line. The separate chamber R1 and the separate chamber R4 communicate with each other via a second communication hole 45c disposed at the height of the FULL line.

Abstract: Provided is a thermostat monitor (36) comprising a thermostat open failure detecting part (38) for detecting an open failure of a thermostat when a condition is such that a radiator heat radiation amount (14) radiated from a radiator on a radiator-side cooling water channel is larger than a heater core heat radiation amount (12) radiated from a heater core on a heater core-side cooling water channel, and that a difference between the radiator heat radiation amount and the heater core heat radiation amount is equal to or more than a predetermined value A. Based on a temperature of engine cooling water detected by a temperature sensor positioned in the vicinity of an outlet of an in-engine cooling water channel, it is possible to detect the open failure of the thermostat relatively easily with certainty.

Abstract: An ignition system for an internal combustion engine includes a prechamber ignition device, a fuel admission valve for the prechamber ignition device, and a combustion consistency control mechanism configured to receive data indicative of at least one of a magnitude of a peak pressure in a combustion prechamber of the prechamber ignition device or a timing of the peak pressure in the combustion prechamber. The combustion consistency control mechanism calculates an error based on the data, and outputs a valve opening command to a fuel valve to produce a shot of combustion-initiating gases from the prechamber device, the valve opening command being based on the error.

Abstract: An intake port of an internal combustion engine is connected to a combustion chamber and includes a connecting portion having a passage cross-sectional area that increases as the connecting portion approaches the combustion chamber, and an upstream portion connected to an upstream end of the connecting portion. The connecting portion is provided at its downstream end with a valve seat with which an umbrella part of an intake valve is brought into contact. At least one recess extending in an extending direction of the intake port and included in the connecting portion and the upstream portion is provided at least at one of two portions, the two portions located on both sides in an extending direction of an output shaft, of a peripheral surface of the intake port.

Abstract: An air intake device includes: an air intake port; and a valve that includes an elastically deformable seal portion disposed in Ha side end portion, and switches between flow paths of the air intake port by being turned around a turning shaft, wherein the side end portion of the valve is provided with a curved side end portion that extends from one end portion side to the other end portion side along an extension direction of the turning shaft while being curved.

Abstract: A turbine housing assembly can include a turbine housing that includes an exterior surface, an interior surface that includes a wastegate seat, and a bore that extends between the interior surface and the exterior surface; a bushing disposed at least partially in the bore where the bushing includes a bushing bore; a wastegate that includes a shaft that extends through the bushing bore to a shaft end, a shaft shoulder disposed in the bushing bore, a plug, and an arm disposed between the shaft and the plug; a ring disposed at least in part in the bushing bore between the shaft shoulder and the shaft end; and a control arm connected to the shaft proximate to the shaft end to define an axial distance between a surface of the control arm and the shaft shoulder where the ring has an axial length that is less than the axial distance.

Abstract: A base portion of the support ring includes as many joining areas as connection pins. The joining areas respectively surround pin holes through which to insert end portions of the connection pins, and are arranged in a circumferential direction of the support ring. Cuts are formed around each joining area of the support ring in order to allow deformation of an intermediate portion of the support ring relative to the joining area.

Abstract: A generator set for a transport refrigeration unit that is operable at a first frequency and a second frequency. The generator set includes a generator and a prime mover. The generator set is controlled by an electronic control unit (ECU) that is coupled to a controller. The ECU is configured to monitor the engine operation condition to obtain an engine operation condition value; whereas the controller is configured to receive the engine operation condition value and compare the value with an engine operation condition threshold. When the engine operation condition value, for example, exceeds the engine operation condition threshold, the controller instructs the ECU to operate the engine at a first speed; and when the engine operation condition value, for example, is below the engine operation condition threshold, the controller instructs the ECU to operate the engine at a second speed that is slower than the first speed.

Abstract: A variable compression ratio internal combustion engine comprises a crankshaft and a connecting rod. The connecting rod comprises a connecting rod body, a first hydraulic cylinder, a first hydraulic piston, a second hydraulic cylinder, a second hydraulic piston, a linking member, a hydraulic oil path, and a spool moving between a first position permitting supply of hydraulic oil from the second hydraulic cylinder to the first hydraulic cylinder, and a second position permitting supply of hydraulic oil from the first hydraulic cylinder to the second hydraulic cylinder. The variable compression ratio internal combustion engine further comprises biasing members arranged at a crank arm or a counterweight of the crankshaft and biasing the spool so as to selectively switch the position of the spool between the first position and the second position.

Abstract: An exhaust purification device of a multi-cylinder engine which improves exhaust gas purification performance by substantially uniforming a flow rate of exhaust gas throughout a treatment carrier such as a catalyst and improving dispersibility of the exhaust gas from the multi-cylinder engine to the catalyst and other components in the exhaust purification device wherein two collecting pipes are arranged at substantially symmetric positions across a partition plate part, which has a linear cross sectional shape, and is arranged centrally between the pipes which are each formed into D-shaped cross sectional shapes and comprise a first straight line part, a pair of second straight line parts connected with respective ends of a first straight line part and arranged to be substantially parallel with each other, and a circular arc part that connects ends of a pair of second straight line parts on opposite sides of the first straight line part.

Abstract: Disclosed are systems and methods for pump control of a closed thermodynamic cycle system, such as a Brayton cycle. Operational parameters such as working fluid temperature, thermal fluid temperature, stream pressure, and power generation may be the basis for controlling a thermal fluid pump rate.

Abstract: A turbocharger (1) with an axial flow turbine stage (2) includes a compressor stage (4) using active casing treatment (50) for choke flow improvement. With switchable slots (52, 54), one of the slots (52) may be between the compressor's full and splitter blades (27, 23) and one of the slots (54) can be located downstream of the compressor's splitter blades (23) to maximize choke flow capacity. In turbochargers with a wastegate assembly, a pneumatic actuator (32) may control both a wastegate control valve (30) and an active casing treatment slot selection valve (56).

Abstract: This IGCC plant is provided with an ASU which separates oxygen gas and nitrogen gas from air, a coal gasification furnace which uses an oxidizing agent to gasify coal, and a gas turbine which is driven by the combustion gas resulting from burning a gas generated by means of the coal gasification furnace. This IGCC plant control device (50) is provided with an air separation amount determination unit (52) which determines the production amount of nitrogen gas produced by the ASU depending on the operating load of the IGCC plant, and supplies to the coal gasification furnace the entire amount of oxygen gas generated as a byproduct in response to the determined nitrogen gas production amount. By this means, the IGCC plant can minimize blow-off of oxygen gas produced from the air.

Abstract: A device for cooling of an annular wall of a turbomachine combustion chamber provided with micro-perforations, and in particular the cooling of a region of the wall facing a wake induced by an ignition plug, the device includes, a deflector designed to divert air immersing the ignition plug towards a median plane of the wake and towards the annular wall of the combustion chamber, so as to increase the air pressure within the wake in proximity to the annular wall.

Abstract: The present invention relates to an assembly (20) for an aircraft turbine engine comprising a fan casing (14) having an inner surface (14b), at least one acoustic panel (26) fastened using fastening elements (48, 54) to the inner surface of the fan casing, and at least one circumferential stiffener (40) of the fan casing (14). According to the invention, the fastening elements (48, 54) connect the fan casing (14) to the stiffener (40) incorporated with the acoustic panel (26).

Abstract: A gas turbine engine that includes a compressor, a turbine, a heat exchanger, and a combustor. The compressor is mounted on a rotating shaft with at least one rotor with an inlet and an outlet, and at least one diffuser downstream from each rotor. The turbine includes at least one stator, and at least one rotor with an inlet and outlet located downstream of each stator, and mounted on the rotating shaft as the at least one of the compressor rotors. The inlet of the compressor rotor faces toward the outlet of the turbine rotor. The heat exchanger is configured to preheat the compressed air leaving the compressor by transferring heat from the turbine exhaust. The combustor can be configured for mixing fuel with the compressed air, either upstream or downstream from the heat exchanger, and further configured for igniting the preheated fuel/air mixture located downstream from the heat exchanger.

Abstract: A heat exchanger assembly in one embodiment includes an inlet, an outlet, and a core. The inlet is configured to accept a fluid to be cooled and the outlet is configured to provide an exit for a flow of the fluid that has been cooled. The core includes at least one passageway formed therein configured for passage of the fluid to be cooled from the inlet to the outlet. The core also includes a receiving surface configured to receive a cooling flow therethrough. The core is configured to direct the cooling flow to pass by at least a portion of the at least one passageway to cool the fluid. The core is comprised of a high temperature geopolymer composite material. The composite material may be configured for use at temperatures above about 300 degrees Celsius, and may have a thermal conductivity below about 20 Watts/(meter*degree Kelvin).

Abstract: Cooling systems for high pressure compressor systems are provided. The cooling systems may comprise tangential on board injectors (“TOBIs”). The TOBIs may comprise one or more fluid channels configured to conduct cooling fluid flow to components of the compressor, including, for example, disk-hub portions of the compressor. In this regard, the TOBI may be configured to exhaust cooling air in a manner such that the exhausted air has a similar linear velocity of the disk-hub portion. The cooling air may also be exhausted in a manner that is substantially parallel to the disk-hub portion.

Abstract: In one exemplary embodiment, a gas turbine engine system for cooling engine components includes an engine core, a core housing containing the engine core, an engine core driven fan forward of the core housing, a nacelle surrounding the fan and the core housing, and a bypass duct defined between an outer diameter of the core housing and an inner diameter of the nacelle. Also included is a thermal management system having a coolant circuit including at least one of a first heat exchanger disposed on the inner diameter of the nacelle and a second heat exchanger disposed on a leading edge of a BiFi spanning the bypass duct. The first heat exchanger is in thermal communication with the second heat exchanger.

Abstract: A tangential on-board injector (TOBI) for a gas turbine engine and methods of making the same are provided. The TOBI includes at least one adjustable strut configured to control an airflow through the TOBI, the at least one adjustable strut moveable to change an airflow characteristic within the TOBI.

Abstract: A method for generating cavitation resistance in a liquid, a portion of which can be in contact with a surface is disclosed. The disclosed method can be carried out by pressure-treating the liquid, the liquid portion in contact with the surface, and/or the surface for a sufficient time to develop resistance to cavitation. The disclosed method can be carried out when the surface is made of a material having a surface roughness that is greater than the rc of the liquid. Suitable surfaces include borosilicate glass, drawn glass, copper, lead, steel, cast iron, metal alloys and concrete. The surfaces can be ship and boat propeller surfaces, the interior of fuel lines and fuel storage containers or any other surface where cavitation can occur.

Abstract: In one aspect the present subject matter is directed to a system for thermally shielding a portion of a shroud assembly for a gas turbine. The system includes a shroud support having a forward wall that includes a front side that is axially spaced from a back side and a radially inner surface that extends axially between the front and back sides. A shroud is mounted to the shroud support. The shroud includes a leading edge portion that extends towards the forward wall of the shroud support and a trailing edge portion that extends towards the aft wall of the shroud support. A radial gap is defined between a top surface of the leading edge portion and the radially inner surface of the forward wall. A thermal shield is disposed along a bottom portion of the forward wall and is oriented to face towards a flow of combustion gases.

Abstract: A gas turbine engine includes a first compressor, a casing surrounding the first compressor, and a liner extending forward from the first compressor. The gas turbine engine also includes a core turbine frame assembly extending between the liner and the casing and a bleed air assembly. The bleed air assembly includes a bleed valve positioned in the liner, and a duct in airflow communication with the bleed valve and defining in outlet. The duct is positioned within the core turbine frame assembly and extends to the casing.

Abstract: A system for predicting performance of a liquid fuel system includes a processor and a memory communicatively coupled to the processor, wherein the memory stores instructions which when executed by the processor perform operations. The operations include establishing a baseline parameter for at least one physical parameter of a nozzle or a valve associated with at least one combustor of the liquid fuel system with at least one time. The operations also include obtaining one or more operational parameters associated with the liquid fuel system from one or more sensors during operation of a gas turbine engine. The operations further include utilizing an operational model of a fuel flow divider to output an action associated with the liquid fuel system based at least on the baseline parameter and the one or more operational parameters.

Abstract: A method for controlling a fuel delivery system of an internal combustion engine, having a fuel delivery pump that is driven by an electric motor. The pressure that prevails in the fuel delivery system is determined by a volume difference between the fuel quantity delivered by the fuel delivery pump and the fuel requirement of the internal combustion engine and/or of the fuel delivery system.

Abstract: A control apparatus for an internal combustion engine, which is capable of, when controlling a variable intake cam phase mechanism and a variable exhaust cam phase mechanism, ensuring a stable combustion of a mixture and improving the drivability, even when one of the two is in a failure state. The control apparatus includes an ECU. The ECU calculates an intake cam phase and an exhaust cam phase, determines, based on the calculated intake cam phase and exhaust cam phase, whether or not there has occurred a failure state of one of the mechanisms, in which the valve overlap period becomes longer than during a normal time, and controls, when it is determined that there has occurred the failure state of the one mechanism, the other mechanism such that the valve overlap period becomes shorter.

Abstract: An engine assembly includes an engine block defining a cylinder, an exhaust system, and an exhaust gas recirculation system. A first exhaust valve is configured to control fluid communication from the cylinder to the exhaust system. A second exhaust valve is configured to control fluid communication from the cylinder to the exhaust gas recirculation system. The second exhaust valve is selectively activatable and deactivatable independently of the first exhaust valve.

Abstract: A system for controlling the combustion behavior of an engine is provided. The engine is equipped with a plurality of control subsystems that influence combustion in the engine. The system includes a controller configured to receive a plurality of inputs, to determine a desired subsystem states to operate the engine, and to determine a target value for each of a plurality of control parameters, wherein the target values for one or more control parameters depends on the values of the plurality of inputs. The controller is further configured to communicate the target values of control parameters to the control subsystems.

Abstract: An evaporated fuel processing apparatus is provided with a blocking valve disposed in a vapor passage. The blocking valve has: a valve whose stroke amount is adjusted by a stepping motor; and a relief valve being opened regardless of the stroke amount when tank pressure of a fuel tank is greater than or equal to a predetermined pressure to allow communication between the fuel tank and a canister. The evaporated fuel processing apparatus is provided with a controller configured (i) to control the stepping motor to move the valve in a valve opening direction while prohibiting a valve opening position learning process when the tank pressure is greater than or equal to the predetermined pressure and (ii) to allow the valve opening position learning process when the tank pressure is less than the predetermined pressure.

Abstract: Systems and methods for activating and deactivating cylinders of an engine that may activate and deactivate one cylinder independent of other cylinders are presented. In one example, an engine cylinder firing fraction and a remainder value that is based on the engine cylinder firing fraction are a basis for activating and deactivating engine cylinders. The systems and methods also provide for transitioning between different cylinder firing fractions.

Abstract: An exhaust gas sensor arrangement structure includes a catalyst which purifies exhaust gas of an engine; and exhaust gas sensors which detect an exhaust gas component of the engine; the catalyst is provided under the engine; and the exhaust gas sensors are provided within a width of the engine in a front/rear direction so that the catalyst is provided between the exhaust gas sensors at front and rear sides of the catalyst.

Abstract: A control system and method utilize an exhaust oxygen (O2) sensor and a controller configured to operate a turbocharged engine in a scavenging mode, and while the operating the engine in the scavenging mode: command a target in-cylinder air/fuel ratio (FA) for achieving a target exhaust gas FA, adjust the measurement of the exhaust O2 sensor based on a scavenging ratio and the target in-cylinder FA to obtain a modified O2 concentration, adjust an exhaust system temperature modeled by a thermal model to obtain a modified exhaust system temperature, and adjust the target in-cylinder FA based on the modified O2 concentration and the modified exhaust system temperature.

Abstract: A failure diagnosis apparatus for an internal combustion engine is provided. The internal combustion engine is mounted on a vehicle. The failure diagnosis apparatus includes an electronic control unit. The electronic control unit is configured to: measure an abnormal time in which an abnormal state where an accelerator pedal operation amount is equal to or larger than a first specified operation amount and a rate of actual output torque to requested torque is smaller than a specified rate value continues; and record specified data for a failure diagnosis of the internal combustion engine on a recording device in the cases where the abnormal time is equal to or longer than a first specified time that is set in advance and the accelerator pedal operation amount is equal to or larger than a second specified operation amount that is larger than the first specified operation amount.

Abstract: Methods and systems for an engine are provided for monitoring cylinder valve deactivation of an engine. One example method includes, responsive to a request to diagnose a cylinder valve actuator of an engine during a non-fueling condition of the engine, commanding an EGR valve open and determining a first exhaust gas flow, and deactivating one or more cylinder valves and indicating cylinder valve actuator degradation when a second exhaust gas flow is not less than a threshold relative to the first exhaust gas flow.

Abstract: A method for a fuel system is provided, wherein a fuel vapor canister is vented to an engine intake during a first condition, and wherein a restriction in a canister vent pathway is indicated, responsive to a change in a fuel tank pressure transducer output greater than a threshold. If the fuel tank pressure transducer output changes less than the threshold, degradation of the fuel tank pressure transducer is indicated. In this way, a fuel tank pressure transducer offset may be distinguished from a canister vent pathway restriction if a fuel tank pressure transducer indicates a significant pressure or vacuum in a fuel tank following a vehicle-off soak.

Abstract: A method and a device for determining the minimum hydraulic injection interval of a piezo-servo injector are described. The closing time of the nozzle needle of the injector is determined on the basis of the characteristic pressure profile in the control spring chamber of the injector. By incrementally reducing the injection interval of a subsequent injection by successively advancing the timing of the start of actuation of a subsequent injection and continuing to observe the pressure profile in the control spring chamber, the smallest injection interval is obtained from the last iteration step in which closing of the nozzle needle of the preceding injection could still be detected in the characteristic pressure profile. Particularly precise determination of the minimum injection interval is possible with this method.