A split cycle internal combustion engine comprises a combustion cylinder and a compression cylinder arranged to receive air and compress the air to provide a compressed working fluid to the combustion cylinder for combustion. The compression cylinder is coupled to a water reservoir. The engine further comprises a controller arranged to receive an indication of at least one parameter associated with the engine and/or a fluid associated therewith, and control delivery of the mass of water delivered to the compression cylinder based on the indication of the at least one parameter such that the total mass of water in the compressed working fluid at the end of the compression stroke results in a level of water concentration in the compressed working fluid that is less than a threshold water concentration level.

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, and a property adjusting device, an accelerator opening sensor, and a controller. The controller performs a combustion control for controlling the injector, the spark plug, and the property adjusting device so that a target torque set based on a present accelerator opening detected by the accelerator opening sensor is outputted in a specific cycle in the future from a present time by a given delay time. In the combustion control, the controller sets a target load of the engine in the specific cycle based on the present accelerator opening, and sets a combustion transition from the present cycle to the specific cycle by selecting beforehand combustion from the present cycle to the specific cycle, from flame propagation combustion and compressed self-ignition combustion, based on the set target load.

Systems and methods are provided for diagnosing cylinders in an engine. In one example, the method may include selecting a cylinder of the engine for perturbation, and while maintaining a horsepower output of the engine, perturbing the cylinder. Responsive to the perturbation of the cylinder inducing a crankcase pressure difference greater than or equal to a threshold difference, a degradation condition of the cylinder may be indicated. In one example, the perturbation may include cutting fuel to the cylinder. In one example, an engine load may be redistributed among each of remaining cylinder of a plurality of cylinders of the engine to maintain the horsepower output of the engine.

A method to determine the mass of air trapped in each cylinder of an internal combustion engine, which comprises determining, based on a model using measured and/or estimated physical quantities, a value for a first group of reference quantities; determining, based on the model, the actual inner volume of each cylinder as a function of the speed of rotation of the internal combustion engine and of the closing delay angle of the intake valve; and calculating the mass of air trapped in each cylinder as a function of the first group of reference quantities and of the actual inner volume of each cylinder.

Systems and methods are described for operating a turbocharger. A current exhaust manifold pressure is determined based on an engine operating condition. A current operating condition of the turbocharger is determined. A surge correction factor is determined based on the current operating condition of the turbocharger. The current exhaust manifold pressure is adjusted based on the surge correction factor.

Systems and methods for lubricant dilution detection are disclosed. A method for detecting lubricant dilution for a lubrication system includes detecting a low idle condition. The method includes receiving sensed values indicative of lubricant pressure and lubricant temperature during the low idle condition. The method also includes determining a lubricant pressure threshold based on the sensed value indicative of lubricant temperature. The method further includes determining lubricant dilution based on the sensed value indicative of lubricant pressure and the determined lubricant pressure threshold during the low idle condition. In accordance with a determination that there is lubricant dilution, the method includes outputting an indication of the lubricant dilution.

A method for operating the two stroke engine provides that the fuel valve is controlled after the starting process in at least a quasi-steady state such that, on the basis of uninterruptedly successive blocks of successive revolutions of the crankshaft, the fuel valve is opened and closed exactly once within each block. Each block includes from two to twenty revolutions of the crankshaft. The fuel valve is opened over a crankshaft angle (α) of more than 360° within one block in at least one operating state. A control device is provided for controlling the fuel valve. A quasi-steady state of the two stroke engine is a state in which the throttle element is adjusted by less than 10% of the maximum adjustment of the throttle element over a crankshaft angle (α) of 360°.

Fuel reform apparatus includes: internal combustion engine including injector and configured so that compression-ignition combustion is carried out in combustion chamber; reform unit interposed in fuel supply path from fuel tank to injector and including reformer reforming fuel stored in fuel tank by oxidation reaction; and controller including CPU and memory. Controller performs: estimating progress level of oxidation reaction in reformer; and controlling operation of reform unit based on progress level of oxidation reaction estimated.

To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.

To provide a controller and a control method for internal combustion engine which can reduce arithmetic load, while suppressing deterioration in the estimation accuracy of the parameter relevant to the combustion state, even if the error component of high frequency is included in the crank angle acceleration. A controller for internal combustion engine, by referring an unburning condition data, calculates a shaft torque in unburning in the vicinity of the top dead center in the burning condition; calculates an external load torque based on calculated shaft torque in unburning and the actual shaft torque in burning in the vicinity of the top dead center; calculates a shaft torque in unburning by referring the unburning condition data; calculates an increment of gas pressure torque by burning based on the shaft torque in unburning, the actual shaft torque in burning, and the external load torque.