Abstract: A method for detecting the blending level of biodiesel fuel in an internal combustion engine includes setting at least two post injection fuel quantity reference values respectively for known biodiesel blending percentage levels. A post injection fuel quantity value is evaluated and is compared with the at least two post injection fuel quantity reference value. A predetermined correlation set of values between the post injection fuel quantity value and a biodiesel blending level expressed by biodiesel percentage with respect to the petro-diesel is used to determine the biodiesel blending level.

Abstract: The invention relates to a method for starting an internal combustion engine associated with means for adapting, during an engine start operation, an amount of fuel injected based on an estimation of the volatility (PVR) of the fuel based on the comparison between a gradient of the engine speed measured upon a preceding start operation and a reference gradient (110) corresponding to a predetermined fuel, characterized by the step (111) of correcting the reference gradient based on a change (?CMF) in the engine friction torque.

Abstract: Fuel systems and methods for controlling fuel systems in a vehicle with multiple fuel tanks are provided. An exemplary vehicle fuel system includes a first fuel tank including a first pressure sensor, and a second fuel tank. The system may further include a fuel tank isolation valve positioned to selectively decouple the first fuel tank and the second fuel tank. The system may further include an electronic controller configured to identify which of the first fuel tank and second fuel tank includes a fuel system leak by selectively decoupling the first fuel tank and the second fuel tank via the fuel tank isolation valve, responsive to an identification of the fuel system leak.

Abstract: A method for predicting a quantity of a contaminant in a fuel tank at the end of a time period, the method comprising the steps of: determining a quantity of the contaminant in the fuel tank at the start of the time period; determining at least one operating condition of the fuel tank during the time period; using information relating to the at least one operating condition of the fuel tank to generate a predicted quantity of the contaminant accumulated in the fuel tank during the time period; and calculating, based upon the quantity of the contaminant at the start of the time period and the predicted quantity of the contaminant accumulated during the time period, a predicted quantity of the contaminant at the end of a time period.

Abstract: A method and apparatus for identifying a component failure within a thermal regenerator operates as follows. The burner control unit monitors at least one of a fuel pump characteristic for a fuel pump and an ignition system characteristic for an ignition system. The fuel pump is used to supply fuel to a fuel-fired burner and the ignition system is used to ignite fuel supplied to the fuel-fired burner. The fuel pump characteristic is communicated to the burner control unit which compares the fuel pump characteristic to a predetermined fuel pump criteria. The ignition system characteristic is communicated to the burner control unit which compares the ignition system characteristic to a predetermined ignition system criteria. The burner control unit identifies a fuel pump failure when the fuel pump characteristic does not meet the fuel pump criteria, and identifies an ignition system failure when the ignition system characteristic does not meet the ignition system criteria.

Abstract: A method for determining the ignitability of a fuel, in particular a self-igniting fuel, based on the ignition delay of the fuel during the combustion in a test engine. According to the invention, the ignition delay is determined from the combustion curve and/or the heat curve.

Abstract: Internal combustion engines which are operated using ethanol exhibit an improved capability for lean-burn running. The lean-burn running limit with a higher ethanol proportion is displaced in the direction of lean. This link between the lean-burn running limit and the ethanol proportion of the fuel is used to determine the ethanol proportion. To determine the lean-burn running limit, a fuel quantity is injected into a cylinder in the operating range of the overrun fuel cut-off, with which fuel quantity no combustion of the air/fuel mixture occurs, and the fuel quantity is increased continuously until combustion occurs; the smooth running of the engine is monitored for this cylinder and the lean-burn running limit is detected as reached if the smooth running exceeds a predefined threshold value. The ethanol proportion is then deduced from the increase in the injected fuel quantity which is required to reach the lean-burn running limit.

Abstract: A method for determining the amount of fuel flow from a high pressure gas tank to the anode side of a fuel cell stack through pulsed injector. The anode sub-system pressure is measured just before the injector pulse and just after injector pulse and a difference between the pressures is determined. The difference between the pressures, the volume of the anode sub-system, the ideal gas constant, the anode sub-system temperature, the fuel consumed from the reaction in the fuel cell stack during the injection event and the fuel cross-over through membranes in the fuel cells of the fuel cell stack are used to determine the amount of hydrogen gas injected by the injector.

Abstract: In a method to determine the temperature of a fuel in a common rail injection system of an engine, the fuel temperature at one place of the common rail injection system is calculated from a fuel temperature at another place of the common rail injection system.

Abstract: The present invention aims at providing an apparatus for detecting abnormality capable of accurately detecting whether or not there is an abnormality in a fuel property detecting apparatus. An apparatus for detecting abnormality for a fuel property detecting apparatus according to the present invention includes the fuel property detecting apparatus having a sensor part provided on a fuel channel, temperature detecting means for detecting the temperature of the fuel in the vicinity of said sensor part, a heater capable of raising the temperature of the fuel in the vicinity of the sensor part, and abnormality determining means for determining whether or not there is an abnormality in the fuel property detecting apparatus based on the temperature detected by the temperature detecting means when the heater is activated.

Abstract: A cetane number estimation method is provided in which: the preliminary injection is preformed multiple times at different compression end temperatures with a fuel tank (26) containing fuel having a predetermined cetane number, and an engine torque increase caused by each preliminary injection is calculated and the relation between the compression end temperatures at the respective preliminary injections and the engine torque increases caused by the respective preliminary injections is determined; the compression end temperature and the engine torque increase at a predetermined reference point on the relation are recorded as a basic compression eng temperature and a basic engine toque increase; the preliminary injection is performed at the basic compression end temperature and an engine torque increase caused by this preliminary injection is calculated; and the cetane number of fuel is estimated based on the relation between the calculated engine torque increase and the basic engine torque increase.

Abstract: A minute amount of fuel is injected into a combustion chamber during fuel cut, and a cylinder pressure is detected when the minute amount of fuel is being combusted. Then a combustion ratio is calculated based on the detected cylinder pressure, and a determination crank angle, which is used for determining a cetane number based on the combustion ratio, is determined. The cetane number is determined based on the determination crank angle.

Abstract: The invention aims at providing an engine control experimenting apparatus which enables to easily carry out a confirmation test of an operation in all operation states with regard to the performance of various engine control parts constituting an engine system. In this engine control experimenting apparatus, various engine control parts, which are actually mounted on an engine and are required for engine control, are constructed in a state where electrical transmission and fuel supply are enabled in a manner similar to a case where the engine control parts are mounted on a real engine, and a model-based control is performed on the same conditions as those of the actual engine, on the basis of experimental data of the real engine written in an electronic control unit constituting each of the engine control parts.

Abstract: A device detecting a property of fuel in a course of a pipeline, while improving accuracy and stability of the fuel property detection. The device includes a sub-tank provided in the course of a fuel pipeline connecting a fuel tank and an engine, and a sensor capable of detecting the property of fuel inside the sub-tank. The sub-tank includes a fuel inlet for introducing therethrough fuel from the fuel tank, and a fuel outlet for sending out therethrough the fuel toward the engine.

Abstract: A fuel temperature sensing device has fuel temperature sensors provided to respective cylinders for sensing fuel temperature. Each fuel temperature sensor is arranged in a position closer to an injection hole than to a pressure accumulator in a fuel passage extending from the pressure accumulator to the injection hole. The device has an average value calculating section for calculating an average value of fuel temperature sensing values sensed with the fuel temperature sensors of the respective cylinders. The device has a deviation calculating section for calculating deviations between the average value and the fuel temperature sensing values of the respective fuel temperature sensors. The device has a correcting section for correcting the fuel temperature sensing value of each fuel temperature sensor to approximate the deviation to zero for each fuel temperature sensor.

Abstract: An alcohol density sensor for detecting an alcohol density in mixture fuel composed of petroleum-fuel and alcohol is installed in a fuel tank of an automotive vehicle. The alcohol density sensor includes a pair of electrodes immersed in the mixture fuel and a conductor portion for connecting the electrodes to a control unit having a circuit board. The conductor portion is composed of a first conductor portion integrally formed with the electrode and a second conductor portion connected to the first conductor portion. The first conductor portion is led out of a casing containing the electrodes and liquid-tightly sealed at a first through-hole formed in the casing. The second conductor portion is led out of the fuel tank through a second through-hole formed in the fuel tank. Since the first through-hole is sufficiently sealed to prevent pressurized mixture fuel in the casing from leaking into an inner space of the fuel tank, sealing of the second through-hole can be simplified.

Abstract: A method of testing and proving fuel efficiency improvements includes installing a telematic device in each of a first plurality of vehicles and a second plurality of vehicles. The telematic devices collect baseline fuel consumption data during a first time period and collect test fuel consumption data during a second time period. Between the first and second time periods, at least one operating parameter of the second plurality of vehicles is modified such that the baseline fuel consumption data and the test fuel consumption data can be analyzed to determine any fuel efficiency improvements caused by the modified operating parameter. To ensure reliable and statistically-significant results, each plurality of vehicles may include 15 vehicles and each time period may include 60 days.

Abstract: The present invention provides a malfunction diagnosing apparatus for an engine which enables selection of a fuel to be supplied to a tank from fuels having different properties. The apparatus includes a determining unit determining whether fuel has been supplied to the tank, a sensor detecting a property of the fuel supplied from the tank to an injection valve, an air-fuel ratio control unit determining an air-fuel ratio correction amount according to a difference between a target air-fuel ratio and an actual air-fuel ratio and according to the property of the fuel sensed by the sensor to correct a fuel injection quantity using the air-fuel ratio correction amount, and a diagnosing unit that definitively diagnoses malfunctions of the determining unit, the sensor, and a fuel system, based on a combination of a determination by the determining unit, detection by the sensor, and the air-fuel ratio correction amount or the difference.

Abstract: A control unit executes sensing of a fuel property of fuel based on a physical value, which is related to a combustion state of the fuel in an internal combustion engine, when it is determined that a predetermined prerequisite operational condition for the sensing of the fuel property is satisfied upon occurrence of at least one of consumption of a predetermined amount of fuel, traveling of a vehicle through a predetermined travel distance, and execution of a predetermined number of operation cycle(s). The predetermined prerequisite operational condition may be satisfied when an operational state of the internal combustion engine is a deceleration fuel cut-off state or an idle state.

Abstract: An internal combustion engine (1) is provided with an in-cylinder pressure sensor (15) for detecting an in-cylinder pressure in a combustion chamber (3) and an ECU (20). The ECU 20 calculates a heat release quantity parameter showing a combustion state based upon a detected in-cylinder pressure, calculates a combustion delay based upon the detected in-cylinder pressure, and determines fuel property based upon a comparison between a calculated heat release quantity parameter and the calculated combustion delay; and a heat release quantity parameter and a combustion delay corresponding to reference fuel.

Abstract: A method for estimating the composition of a fuel within an engine, comprises performing the following steps under ambient conditions: (a?) determining the ambient temperature of the fuel; (a) monitoring the fuel pressure inside a fuel rail of the engine over a period of time; (b) calculating at least one frequency component of the change in fuel pressure; (c) calculating the speed of sound transmission c on the basis of the at least one frequency component; and (d) estimating the composition of the fuel on the basis of the calculated speed of sound transmission at said ambient temperature. Suitably, the speed of sound transmission in the fuel is calculated using the equation: c=f?, where the wavelength ? of the standing wave with frequency f is 2L, where L is the length of the fuel rail. Also described are methods for estimating the temperature of the fuel at a non-ambient temperature, and determining a fuels physical properties.

Abstract: A method for diagnosing a condition of a system for supplying fuel to a fuel injected controlled-ignition internal combustion engine, of a type including an electric control device that makes use of an oxygen probe for closed-loop regulation of a value of air/fuel ratio admitted to combustion chambers of the engine, and according to which a signal delivered by an oxygen probe is analyzed, the method a) deducing from the signal, a change in a effective injection time making it possible to regulate richness of exhaust gases leaving the engine; b) calculating CRITERION=?(CRITERION 1+CRITERION2+CRITERION3); c) comparing CRITERION against predetermined minimum and maximum threshold values THRESHOLD_MIN and THRESHOLD_MAX; d) diagnosing a defective condition when CRITERION is outside of a window included between THRESHOLD_MIN and THRESHOLD_MAX.

Abstract: A method of operating a fuel injected multi-cylinder internal combustion engine includes electronically storing a first value or reference value indicative of an engine speed response to a commanded fueling duration change during fueling the engine with a first fuel or reference fuel, such as a known type of diesel fuel. The method further includes operating the internal combustion engine in a fuel testing mode during fueling with a second fuel or test fuel, such as an unknown type of diesel fuel. The fuel testing mode includes determining a second value or test value indicative of an engine speed response to a commanded fueling duration change, comparing the test value with the reference value and outputting a fuel attribute signal which is based at least in part on comparing the reference value and the test value.

Abstract: The invention relates to a method for the open-loop control of an internal combustion engine, which is operated with a fuel blend of an initial and at least one second fuel, the internal combustion engine having a fuel metering system, a tank fill-level gauge for determining the tank content and a change in the tank content, a sensor for the detection of the cylinder charge for determining an air mass supplied to the internal combustion engine and at least one exhaust gas probe for determining and controlling the oxygen content in the exhaust gas in a closed-loop. According to the invention, two methods, which are independent from each other, are used for determining the composition of the fuel blend.

Abstract: There is disclosed a fuel property detector for detecting a property of fuel injected by a fuel injector into a cylinder of an internal combustion engine. The fuel property detector includes an injection commander, a change detector, and a fuel property determiner. The injection commander commands the fuel injector to perform a fuel injection for fuel property detection into the cylinder of the engine. The change detector detects a change in the rotational speed of the engine which is caused by the fuel injection for fuel property detection. The fuel property determiner determines the property of the fuel based on the change in the rotational speed of the engine detected by the change detector.

Abstract: An air/fuel imbalance detection module includes a fueling control module, a response time determination module, and a comparison module. The fueling control module commands a fueling change according to a predetermined fueling pattern. The response time determination module determines a measured response time for a wide-range air/fuel sensor (WRAF) to output a predetermined voltage. The comparison module compares the measured response time with a reference time range and diagnoses air/fuel imbalance when the measured response time is outside the reference time range.

Abstract: A solenoid valve includes cyclically energizing and deenergizing a solenoid of the solenoid valve to repeatedly fully open and fully close the solenoid valve. When the energizing and deenergizing causes collisions of a moving member of the solenoid valve against at least one of a first and a second seat formed in a housing of the solenoid valve, noises are thus generated by the collisions and occurrence intervals of the noises are detected. Whether the solenoid valve is in normal or abnormal condition is diagnosed based on the detected occurrence intervals of the noises.

Abstract: An abnormality diagnosis apparatus for an internal combustion engine includes an abnormality diagnosis unit, an other fuel contamination determination unit, and a misdiagnosis prohibition unit. The abnormality diagnosis unit determines whether there is an abnormality in a fuel system based on an output from an exhaust gas sensor mounted on an exhaust duct of the internal combustion engine. The other fuel contamination determination unit determines whether an other fuel contaminates a supply fuel supplied to the internal combustion engine. The misdiagnosis prohibition unit conducts one of (a) changing an abnormality determination condition for the abnormality diagnosis in the fuel system and (b) prohibiting the abnormality diagnosis in the fuel system, when the other fuel contamination determination unit determines that the other fuel contaminates the supply fuel.

Abstract: A fuel injection apparatus includes an accumulator, an injector, a fuel supplier supplying fuel to the accumulator, and a controller controlling a fuel supply rate of the fuel supplier through manipulation of a manipulated variable. The controller is configured to set a target fuel supply rate, determine a base target value of the manipulated variable as a first function of the target fuel supply rate, determine a correction value as a second function of the target fuel supply rate, correct the base target value of the manipulated variable using the correction value to obtain a final target value of the manipulated variable, and manipulate the manipulated variable to have the final target value, thereby bringing the fuel supply rate of the fuel supplier into agreement with the target fuel supply rate. The first and second functions are predefined prior to the installation of the fuel injection apparatus to an engine.

Abstract: The present invention provides a malfunction diagnosing apparatus for an engine which enables selection of a fuel to be supplied to a tank from fuels having different properties. The apparatus includes a determining unit determining whether fuel has been supplied to the tank, a sensor detecting a property of the fuel supplied from the tank to an injection valve, an air-fuel ratio control unit determining an air-fuel ratio correction amount according to a difference between a target air-fuel ratio and an actual air-fuel ratio and according to the property of the fuel sensed by the sensor to correct a fuel injection quantity using the air-fuel ratio correction amount, and a diagnosing unit that definitively diagnoses malfunctions of the determining unit, the sensor, and a fuel system, based on a combination of a determination by the determining unit, detection by the sensor, and the air-fuel ratio correction amount or the difference.

Abstract: Systems and methods for determining a plurality of characteristics of a fuel and controlling a fuel delivery system based on the characteristics of the fuel. A controller generates a plurality of control signals. The control signals are transmitted to at least one ultrasonic transducer, a capacitance sensor, and a temperature sensor. Each of the ultrasonic transducer, capacitance sensor, and temperature sensor generate at least one output signal which is transmitted back to the controller. The controller determines, based on the output signals, the plurality of characteristics of the fuel. The characteristics of the fuel can include, for example, temperature, density, dielectric constant, and the like. The controller then compares the characteristics of the fuel to a set of characteristics of a first fuel type and a second fuel type and controls a fuel delivery device based on the characteristics of the fuel.

Abstract: The present disclosure, in one implementation, is directed to a method of estimating composition of fuel in the fuel tank of a vehicle. A refuel event is detected. A determination is made whether a volume of fuel added to the fuel tank satisfies a first threshold. A fuel composition estimation is suspended if the refuel event satisfies the first threshold. A total volume of fuel is accumulated based on a plurality of refuel events satisfying the first threshold. A new fuel composition is estimated based on the accumulated total volume of fuel satisfying a second threshold.

Abstract: In a method and a device which allow determination of the combustion lambda value of an internal combustion engine having at least two combustion chambers without using a lambda sensor, a predetermined first fuel quantity is metered to the first combustion chamber and a predetermined second fuel quantity is metered to the second combustion chamber, the first fuel quantity is reduced by a predetermined amount and the second fuel quantity is increased by the same predetermined amount. A first engine noise, associated with the first combustion chamber, and a second engine noise, associated with the second combustion chamber, are determined. The combustion lambda value is determined based on the first engine noise value and second engine noise value.

Abstract: A control unit executes sensing of a fuel property of fuel based on a physical value, which is related to a combustion state of the fuel in an internal combustion engine, when it is determined that a predetermined prerequisite operational condition for the sensing of the fuel property is satisfied upon occurrence of at least one of consumption of a predetermined amount of fuel, traveling of a vehicle through a predetermined travel distance, and execution of a predetermined number of operation cycle(s). The predetermined prerequisite operational condition may be satisfied when an operational state of the internal combustion engine is a deceleration fuel cut-off state or an idle state.

Abstract: This invention provides an electric fuel pump tester that allows a technician to simulate the real-life operation of the electrical system of the vehicle, i.e., when the fuel pump is installed. The present invention provides a tester that includes a load that is similar to that of an installed fuel pump. In this manner, a technician may monitor simulated real-life operation of the vehicle's electrical system.

Abstract: A fuel delivery device 11 has a delivery pipe 18, which supplies fuel to a fuel injection valve 21 of an internal combustion engine 10. An electromagnetic relief valve 22 releases the fuel from the delivery pipe 18 in response to an opening instruction and lowers the pressure of the fuel in the delivery pipe 18. A diagnosis device for the relief valve 22 has an electronic control unit 27 outputting the opening instruction to the relief valve 22 in response to a stopping instruction for stopping the engine 10. The unit 27 determines whether the relief valve 22 has a defect based on a manner in which the pressure of the fuel in the delivery pipe 18 changes after output of the stopping instruction. As a result, it is appropriately diagnosed whether the electromagnetic relief valve 22 has a defect.

Abstract: The invention relates to a method of ensuring the safety of the components of the drive train of a vehicle equipped with a heat engine, before or during its startup phase following a deterioration of the quality of the fuel contained in the tank (2) and the fuel feed system of the engine, said method comprising a step of diagnosing the type and extent of the deterioration of the quality of the fuel, said step being based on the measurement of the interactions between an electronmagnetic radiation and the constituent molecules of the fuel, said measurement being performed by a system of analysis, and a step of activating a system (13) to ensure the safety of the components of the drive train as a function of the results of the analysis step.

Abstract: An alcohol concentration sensor detecting alcohol concentration of fuel is provided in a fuel tank or a fuel passage. An alcohol concentration detected at a previous driving of an engine is stored in a backup RAM. When a current alcohol concentration is different from the previous alcohol concentration, a procedure of an abnormality diagnosis is prohibited or invalidated until all of the fuel remaining in the fuel passage is consumed.

Abstract: A fuel cetane determination device for an engine is disclosed. In one embodiment, the device comprises a controller that is arranged and configured to determine a rapidness of combustion based on a parameter relating to a combustion state of an engine. The controller is further arranged and configured to determine the cetane value of the fuel in use by the engine based on the rapidness of combustion from a correlation between the rapidness of combustion and the cetane value when the engine is in a first operating condition. The controller is further arranged and configured to determine the cetane value of the fuel in use by the engine based on the rapidness of combustion from a correlation between the rapidness of combustion and the cetane value when the engine is in a second operating condition. The correlation for the second operating condition has a different characteristic tendency from the correlation for the first operating condition. A method is also disclosed.

Abstract: A control system for an internal combustion engine, which makes it possible to estimate a fuel property parameter indicative of a property of fuel in use, in a plurality of operation modes of the engine, respectively, to thereby increase the chances of estimation of the fuel property parameter, and select an appropriate one from the estimated fuel property parameters to thereby more appropriately control the engine. The fuel property parameter is estimated when the detected operating conditions of the engine correspond to any of a plurality of operation modes. Depending on a plurality of fuel property parameters estimated in respective operation modes, one of the fuel property parameters is determined as the fuel property parameter for control of the engine.

Abstract: A fuel delivery device 11 has a delivery pipe 18, which supplies fuel to a fuel injection valve 21 of an internal combustion engine 10. An electromagnetic relief valve 22 releases the fuel from the delivery pipe 18 in response to an opening instruction and lowers the pressure of the fuel in the delivery pipe 18. A diagnosis device for the relief valve 22 has an electronic control unit 27 outputting the opening instruction to the relief valve 22 in response to a stopping instruction for stopping the engine 10. The unit 27 determines whether the relief valve 22 has a defect based on a manner in which the pressure of the fuel in the delivery pipe 18 changes after output of the stopping instruction. As a result, it is appropriately diagnosed whether the electromagnetic relief valve 22 has a defect.

Abstract: An estimation apparatus for determining a residual burned gas mass fraction of an internal combustion engine includes a single-cylinder simulator and an optimizer. The residual estimation apparatus does not rely on accurate knowledge of, or calculation of the details of the complex pulsating pressures and flows at the intake and exhaust valves. Instead an iterative approach uses primarily measured cylinder pressure and airflow as driving inputs, to ensure that the simulation states (i.e., pressure, temperature, and composition) of the cylinder gas contents, at the time of intake valve closing, are correct. The burned gas fraction calculated by the engine simulator is then taken as an estimate of that in the actual engine.

Abstract: The invention relates to a method for testing the mobility of the negative pressure relief valve of the fuel system of a motor vehicle, the negative pressure relief valve depending on the pressure within the fuel system having to be moved between a closed position which closes the fuel system and an open position which clears the fuel system, with the following steps: a) Testing the position of the negative pressure relief valve; and b) Testing the position of the negative pressure relief valve in reaction to a pressure increase within the fuel system if the negative pressure relief valve in step a) was in the closed position. The invention furthermore relates to a system for testing the mobility of the negative pressure relief valve of the fuel system of a motor vehicle.

Abstract: A diagnostic apparatus is combined with a high-pressure fuel supply system including a high-pressure fuel pump, a fuel rail, injectors, and a fuel pressure measuring unit for measuring fuel pressure in the fuel rail. The diagnostic apparatus is capable of detecting troubles in the high-pressure fuel pump and injectors and of discriminating between a trouble in the high-pressure fuel pump and a trouble in the injectors includes.

Abstract: Systems and methods for determining a plurality of characteristics of a fuel and controlling a fuel delivery system based on the characteristics of the fuel. A controller generates a plurality of control signals. The control signals are transmitted to at least one ultrasonic transducer, a capacitance sensor, and a temperature sensor. Each of the ultrasonic transducer, capacitance sensor, and temperature sensor generate at least one output signal which is transmitted back to the controller. The controller determines, based on the output signals, the plurality of characteristics of the fuel. The characteristics of the fuel can include, for example, temperature, density, dielectric constant, and the like. The controller then compares the characteristics of the fuel to a set of characteristics of a first fuel type and a second fuel type and controls a fuel delivery device based on the characteristics of the fuel.

Abstract: The invention relates to a method for determining the degree of cooling during non-operation of an internal combustion engine. Fuel temperature characteristics at and following an engine start are determined, and the degree of cooling during non-operation of the engine is determined based at least partly on the fuel temperature characteristics. Preferably, the determination of fuel temperature characteristics comprises determining the fuel temperature at the engine at a first point in time and determining the fuel temperature at the engine at a second point in time, the second point in time following the first point in time and following a start of the engine.

Abstract: A method for estimating the composition of a fuel within an engine, comprises performing the following steps under ambient conditions: (a?) determining the ambient temperature of the fuel; (a) monitoring the fuel pressure inside a fuel rail of the engine over a period of time; (b) calculating at least one frequency component of the change in fuel pressure; (c) calculating the speed of sound transmission c on the basis of the at least one frequency component; and (d) estimating the composition of the fuel on the basis of the calculated speed of sound transmission at said ambient temperature. Suitably, the speed of sound transmission in the fuel is calculated using the equation: c=f?, where the wavelength ? of the standing wave with frequency f is 2L, where L is the length of the fuel rail. Also described are methods for estimating the temperature of the fuel at a non-ambient temperature, and determining a fuels physical properties.

Abstract: A device for indicating clogging of the fuel filter (1) of internal combustion engines, in particular diesel engines, the filter having an outer casing (2) closed by a cover (3) of amagnetic material, and a filter element (5) which, together with a disc (30) to which it is connected, defines two chambers (6and 7) for fuel entry and exit respectively; the device further includes a pressure sensor (10) sensing the difference between the entry and exit fuel pressure and housed inside the filter casing, and a sensor (21) for generating a signal proportional to the pressure difference which is located outside the filter casing and is not mechanically connected to the pressure sensor.

Abstract: A fuel volatility recognition method during the post-cranking step of an internal combustion engine; the recognition method contemplates the steps of: starting the internal combustion engine; adjusting the enrichment of the mixture burnt in the cylinders of the internal combustion engine according to a previously determined historic fuel volatility value; detecting the time evolution of the angular speed of a crankshaft of the internal combustion engine during the post-cranking step; determining the noise contained in the angular speed of the crankshaft by filtering the angular speed itself by means of a high-pass filter; comparing the noise contained in the angular speed of the crankshaft against at least one predetermined threshold value; and recognizing the fuel volatility according to the result of the comparison between the noise contained in the angular speed of the crankshaft and the predetermined recognition threshold.

Abstract: An engine control module determining an alcohol compensated fuel consumption value includes an alcohol percent module that determines an alcohol percent in fuel and a fuel mass module that determines a mass of the fuel. The engine control module also includes a fuel volume module that calculates a volume of the fuel based on the mass of the fuel, a density of the fuel, and the alcohol percent.