Systems, methods and apparatus for controlling operation of dual fuel engines are disclosed that regulate the fuelling amounts provided by a first fuel and a second fuel during operation of the engine. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The fuelling amounts are controlled to improve operational outcomes of the duel fuel engine.

Methods and systems are provided for operating a driveline of a hybrid vehicle during conditions when a temperature of a motor/generator is increasing. In one example, a method is provided that adjusts engine speed as a function of motor/generator temperature while maintaining engine power output when driver demand wheel power is constant.

An EGR device for a vehicle includes a valve driver, a pressure comparison unit, a freeze determination unit, and an EGR controller. The valve driver drives an EGR valve to open, when fuel cut has been continued for a predetermined time in a state where an engine speed of a vehicle's engine is equal to or higher than a predetermined rotational speed. The pressure comparison unit compares a pre-driving pressure of an engine's intake pipe with a post-driving pressure of the intake pipe. The freeze determination unit sets a flag indicating that the EGR valve is frozen when a difference between the pre-driving pressure and the post-driving pressure is less than a predetermined value and an external temperature is less than a threshold. When the flag has been set, the EGR controller sets a control state of the EGR valve to a closed state and stops EGR control.

A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

A technique for fuel system protection for an internal combustion engine comprises determining direct fuel injector temperature as a function of engine operating parameters; and advancing intake valve timing when the temperature rises above a first predetermined value such that the temperature is maintained below a second predetermined value.

Systems, methods and apparatus for controlling operation of dual fuel engines are disclosed that regulate the fueling amounts provided by a first fuel and a second fuel during operation of the engine. The first fuel can be a liquid fuel and the second fuel can be a gaseous fuel. The fueling amounts are controlled to improve operational outcomes of the duel fuel engine.

The present invention provides a device and method for detecting a misfire in an engine, the device being provided with: a rotation speed sensor (43) as a supercharger rotation speed measurement unit for measuring a rotation speed (Nt) of a supercharger (23); a misfire index calculation unit (51) that calculates a misfire index (Yt) from a degree of change in the rotation speed (Nt) of the supercharger (23), the rotation speed being measured by the rotation speed sensor (43); and a misfire determination unit (52) that determines a misfire in an engine (10) when the misfire index (Yt) calculated by the misfire index calculation unit (51) exceeds a pre-set determination value (D).

A continuously variable valve duration (CVVD) system includes a controller configured to determine whether a learning value existing in the CVVD system is required to be verified during one of a hardware abnormality, a learning value abnormality, and a motor voltage abnormality. In particular, the controller performs a learning value verification control using a rotation detection value and switches from a learning value verification control to a re-learning control when re-learning is required.

Disclosed is a method and a device for predicting the failure time of the pressure limiting valve of a high-pressure fuel pump of a motor vehicle. The method includes measuring a characteristic parameter of the pressure limiting valve each time the motor vehicle has been switched off, determining and storing a variable determined by using the measured characteristic parameter, determining the time profile of the variable determined from the characteristic parameter, predicting the future profile of the variable determined from the characteristic parameter, and comparing the predicted future profile of the variable determined from the characteristic parameter with a predetermined wear limiting value. The comparison is to predict the time at which the predicted future profile of the variable determined from the characteristic parameter reaches the predetermined wear limiting value.

Various embodiments include a method for checking a variable valve lift control of an internal combustion engine comprising: during operation of the internal combustion engine, detecting a rotational speed of the internal combustion engine; and measuring an intake pressure in the intake tract of the internal combustion engine corresponding to the detected rotational speed. The method further includes: defining a reference frequency dependent on the rotational speed of the internal combustion engine; defining a comparison frequency as a non-integral multiple of the reference frequency; determining amplitudes of oscillations of the intake pressure at the reference frequency and amplitudes of oscillations of the intake pressure at the comparison frequency; and evaluating a ratio of the determined amplitudes and the respective absolute values.