There is provided fuel-system failure detection apparatus applied to an engine capable of switching between a first injection mode and a second injection mode, which comprises a first failure determination unit which performs a fuel system failure determination process while the engine is operating in the first and the second injection modes, respectively, a second failure determination unit which, when the first failure determination unit gives a decision of failure while the engine is operating in either of the two injection modes, performs the fuel system failure determination process while the engine is operating in the other injection mode, and a failure identification unit which identifies a failure in fuel systems governing the first and second injection modes respectively, based on a decision about failure given by the second failure determination unit.

A method for the injector-specific diagnosis of a fuel injection device of an internal combustion engine, including the following steps: detecting a pressure progression in an individual accumulator of an injector in a time-resolved manner; evaluating the detected pressure progression; determining if there is a fault state of the injection device in the region of the injector on the basis of the detected and evaluated pressure progression; and identifying the fault state on the basis of the detected and evaluated pressure progression.

An MBT ignition time and a knock ignition time are acquired from an engine rotation speed and engine load, and an ignition time on a delay angle side, out of these ignition times, is set as the most advance angle ignition time. An ignition time on the delay angle side only by the KCS learning value with respect to the most advance angle ignition time is set as a required ignition time, and when an actual ignition time set by a knock control system exceeds a predetermined amount and is positioned on the delay angle side with respect to the required ignition time, it is determined that abnormality occurs in an oil jet. Fail-safe processing to the effect that the opening degrees of a throttle valve are corrected to a closed side is executed in response to the abnormality determination.

A method of calculating a nitrogen oxide (NOx) mass reduced from a lean NOx trap (LNT) during regeneration includes calculating a C3H6 mass flow used to reduce the NOx among a C3H6 mass flow flowing into the LNT of an exhaust purification device, calculating a NH3 mass flow used to reduce the NOx among a NH3 mass flow flowing into the LNT, calculating a reduced NOx mass flow based on the C3H6 mass flow used to reduce the NOx and the NH3 mass flow used to reduce the NOx, and calculating the reduced NOx mass by integrating the reduced NOx mass flow over a regeneration period.

Systems and methods for determining air-fuel error in an engine fueled via direct and port fuel injection. Errors associated with individual fuel injection systems are distinguished from a common error based on trends in the error correction coefficients of the individual fuel injection systems. Adaptive fuel multipliers for each injection system are updated to account for the common error.

A method for controlling a plurality of injectors installed in the same cylinder of an engine may include determining whether an electrical failure occurred in any of the injectors, and entering a fail-safe mode when an electrical failure has occurred only in one of the plurality of injectors in the same cylinder. In the fail-safe mode, fuel supply to an injector that has experienced an electrical failure is cut off, and the amount of fuel injected into the cylinder by a normally operating injector is increased.

To exert combustion control using a CNG injector, a first cutoff valve is opened. On condition that the first cutoff valve is opened, the presence or absence of fuel leakage in a high-pressure side path is determined based on a drop in a detected value of a pressure in the high-pressure side path (high-pressure side detected value PH). Inserting a nozzle for CNG filling into a filling opening causes a phenomenon where the high-pressure side detected value PH rises once and then drops. If the high-pressure side detected value PH rises at a specified rate or more, a CPU stops determination as to the presence or absence of a fuel leakage malfunction for a specified period of time.

A hollow first accommodating case (28) is provided on a front part of a revolving frame (5) at a position on a front side of a fuel tank (23), and a fuel supply pump (34) for supplying a fuel stored in an external fuel storage source to the fuel tank (23) is provided on the fuel tank (23) by being connected. A fuel suction port (35) for sucking the fuel toward the fuel supply pump (34) is provided in the first accommodating case (28) by being opened to an outside, and a urea water tank (25) is provided by being accommodated in the first accommodating case (28). A water supply port (25G) of a urea water is provided in the urea water tank (25) by being opened to the outside, and the fuel suction port (35) and the water supply port (25G) of the urea water are juxtaposed and arranged in the first accommodating case (28).

A method for fuel regulation during a non-motoring operating mode of an internal combustion engine is provided. A fuel regulator employs a first fuel to regulate pressure of a second fuel. The first fuel is communicated to the fuel regulator through a first fuel circuit. The method comprises actuating a fuel injector that introduces the first fuel and the second fuel into a combustion chamber of the internal combustion engine during the non-motoring operating mode. The fuel injector is actuated with an injection command signal having a pulse width below a predetermined maximum value whereby no fuel is injected into the combustion chamber and the first fuel drains from the first fuel circuit through the fuel injector to a supply tank.

A heater control apparatus of a fuel filter for a vehicle includes a heater mounted within a fuel filter; a relay for a heater power source supplying or interrupting power of a battery to or from the heater; a fuel temperature detection sensor mounted on an engine and detecting a temperature of a fuel; and an engine electronic control unit (ECU) for switching on and off the relay based on a detection signal of the fuel temperature detection sensor.