Abstract: A method is provided for adjusting timing of fuel injection into a combustion chamber of a compression-ignition engine. The method includes detecting a request for zero torque generation by the engine and cutting-off delivery of fuel into the combustion chamber during the detected zero torque request. The method additionally includes issuing a command to inject a test quantity of fuel into the combustion chamber during the detected request for zero torque generation. The method also includes assessing a timing delay between the command to inject the test quantity of fuel and a start of the test quantity injection, and determining a compensation for the assessed timing delay. The method additionally includes detecting a request for positive torque generation by the engine. The method further includes commanding a shift in the timing of fuel injection into the combustion chamber by the determined compensation during the engine's positive torque generation.

Abstract: A method using compensation learning strategy for a diagnostic of an internal combustion engine component includes operating the component via an actuator command to establish a first operating parameter representative of a first mode of component operation. The method also includes identifying a drift in the first parameter negatively affecting the first mode of operation. The method additionally includes determining compensation to the actuator command to counteract the first parameter drift during the first mode of operation. The method also includes determining compensation to the first parameter using the determined actuator command compensation. The method additionally includes applying the determined parameter compensation directly to the first parameter. The method also includes operating the component using the actuator command to establish a second operating parameter representative of a second mode of component operation.

Abstract: A method using compensation learning strategy for a diagnostic of an internal combustion engine component includes operating the component via an actuator command to establish a first operating parameter representative of a first mode of component operation. The method also includes identifying a drift in the first parameter negatively affecting the first mode of operation. The method additionally includes determining compensation to the actuator command to counteract the first parameter drift during the first mode of operation. The method also includes determining compensation to the first parameter using the determined actuator command compensation. The method additionally includes applying the determined parameter compensation directly to the first parameter. The method also includes operating the component using the actuator command to establish a second operating parameter representative of a second mode of component operation.

Abstract: A method of determining combustion efficiency in an engine includes utilizing a control module having a computer memory, a processor, and inputs and outputs, the processor executing logic stored within the memory, sensing data by first sensors disposed on the engine and second sensors disposed in an exhaust system fluidly coupled to the engine, the first and second sensors electrically connected to the inputs, receiving within the control module data sensed by the first and the second sensors; determining an oxygen content of air entering the engine, determining an oxygen content of exhaust upstream of an oxidation catalyst; determining a fuel latent heat of vaporization; determining a fuel injection quantity to combust with oxygen entering the engine; determining a combustion efficiency index based on the oxygen content of air entering the engine and in the exhaust, and the latent heat of vaporization of fuel; and adjusting a fuel injection quantity.

Abstract: A method of operating a fuel injector of an internal combustion engine includes setting a value of a target fuel quantity to be injected by the fuel injector, initializing a value of a fuel quantity requested from the fuel injector to the value of the target fuel quantity, and correcting the value of the requested fuel quantity. A first learning cycle is performed to correct the value of the requested fuel quantity in which a difference between the target fuel quantity and the injected fuel quantity is calculated and added to the requested fuel quantity to provide a corrected value. The corrected value of the requested fuel quantity is used to determine a reference value of an energizing time that causes the fuel injector to inject a fuel quantity corresponding to the target fuel quantity. The fuel injector is operated based on the determined reference value of the energizing time.

Abstract: A method and apparatus is disclosed for testing a fuel injector of an internal combustion engine equipped with a plurality of fuel injectors to detect injector clogging. A test injector is switched off. A requested value of a fuel quantity to be injected by the other fuel injectors of the plurality of fuel injectors is adjusted to operate the internal combustion engine in idle mode. A value of an oxygen concentration in an exhaust gas is measured. A value of a fuel quantity that has been injected is estimated as a function of the measured value of the oxygen concentration. A fuel quantity drift of each fuel injector is calculated as a function of the requested values and the estimated values of the fuel quantity provided by the injector tests. Each fuel quantity drift is used to identify if the corresponding fuel injector is clogged.

Abstract: A first test injection of a fuel injector is performed with a first test Energizing Time and the actual fuel quantity injected is measured to obtain a first point of a characteristic curve representing a relationship between the injector Energizing Time and the fuel quantity which is actually injected. A ratio between the actual fuel quantity injected and a nominal fuel quantity corresponding to the first test Energizing Time is calculated and used to determine a plurality of corrected Energizing Times for subsequent test injections. The subsequent test injections are performed using the corrected Energizing Times and the actual fuel quantity that has been injected during each one of the subsequent test injections is measured to obtain further points of the characteristic curve. The characteristic curve of the fuel injector is modeled based on the obtained further points and used to control the operation of the fuel injector.

Abstract: A method and apparatus is disclosed for testing a fuel injector of an internal combustion engine equipped with a plurality of fuel injectors to detect injector clogging. A test injector is switched off. A requested value of a fuel quantity to be injected by the other fuel injectors of the plurality of fuel injectors is adjusted to operate the internal combustion engine in idle mode. A value of an oxygen concentration in an exhaust gas is measured. A value of a fuel quantity that has been injected is estimated as a function of the measured value of the oxygen concentration. A fuel quantity drift of each fuel injector is calculated as a function of the requested values and the estimated values of the fuel quantity provided by the injector tests. Each fuel quantity drift is used to identify if the corresponding fuel injector is clogged.

Abstract: A method of operating a fuel injector of an internal combustion engine includes setting a value of a target fuel quantity to be injected by the fuel injector, initializing a value of a fuel quantity requested from the fuel injector to the value of the target fuel quantity, and correcting the value of the requested fuel quantity. A first learning cycle is performed to correct the value of the requested fuel quantity in which a difference between the target fuel quantity and the injected fuel quantity is calculated and added to the requested fuel quantity to provide a corrected value. The corrected value of the requested fuel quantity is used to determine a reference value of an energizing time that causes the fuel injector to inject a fuel quantity corresponding to the target fuel quantity. The fuel injector is operated based on the determined reference value of the energizing time.

Abstract: A first test injection of a fuel injector is performed with a first test Energizing Time and the actual fuel quantity injected is measured to obtain a first point of a characteristic curve representing a relationship between the injector Energizing Time and the fuel quantity which is actually injected. A ratio between the actual fuel quantity injected and a nominal fuel quantity corresponding to the first test Energizing Time is calculated and used to determine a plurality of corrected Energizing Times for subsequent test injections. The subsequent test injections are performed using the corrected Energizing Times and the actual fuel quantity that has been injected during each one of the subsequent test injections is measured to obtain further points of the characteristic curve. The characteristic curve of the fuel injector is modeled based on the obtained further points and used to control the operation of the fuel injector.