A method for detecting reverse flow for a dual fuel engine is disclosed. The engine may include an intake manifold, a liquid fuel supply line and a gaseous fuel supply line, the gaseous fuel supply line including a gaseous fuel supply and a gaseous fuel rail. The method may include: operating the dual fuel engine in a liquid fuel only mode via the liquid fuel supply line; determining a reverse flow in the gaseous fuel supply line; and outputting an indication of reverse flow in response to the determination of reverse flow.

A valve system of a fuel system for a vehicle may close a jet pump-side flow path when a pressure of fuel supplied from a fuel pump to an engine is lower than a prescribed fuel pressure at engine start-up, and open the jet pump-side flow path when the pressure of fuel is equal to or higher than the prescribed fuel pressure at the engine start-up, thereby improving cold startability of an engine, and may also allow the jet pump-side flow path to be kept in an opened state between a low load region and a high load region of the engine after the engine start-up, thereby smoothly keeping a function of the jet pump after the engine start-up.

An engine includes a reformer, a reforming-air adjuster, a reforming-fuel supply unit, a reformed-gas adjuster, and a control unit. The reformer is configured to reform fuel into a reformed gas. When a start signal is input, the control unit controls the reforming-air adjuster and the reforming-fuel supply unit to a reformable state in which the fuel is reformable in the reformer, and the control unit controls the reformed-gas adjuster so that the reformed gas flows through the reformed-gas adjuster with a degree of opening smaller than a normal degree of opening that is a degree of opening of the reformed-gas adjuster when composition of the reformed gas is in a stable state before the composition of the reformed gas becomes in the stable state, for a given period of time including at least a period immediately after the engine starts.

An automatic drain device is configured for use with a fuel water separator filter system. The automatic drain device includes a solenoid, a water-in-fuel sensor, and a controller configured to operate the automatic drain device by activating the solenoid in response to a signal from the water-in-fuel sensor. The automatic drain device may be utilized with suction side and pressure side fuel water separator filter systems. The automatic drain device operates independently of any user input.

A synchronous dynamometer assembly for applying a load to an engine during at least one portion of the combustion cycle of the engine in a synchronised manner so as to be repeatable each cycle of the engine comprises a dynamometer having a non-inductive load which is applied to the engine during operation to vary the speed of the engine. The non-inductive load is variable by varying the current delivered to it. Crankshaft monitoring means monitors the rotational position of the engine crankshaft, and combustion detection means detects a combustion event in a cylinder of the engine. Control means is operatively connected to the dynamometer for applying the load from the dynamometer to the engine for at least one part of the combustion cycle in real time such that the different loads may be applied to the engine for different parts of the combustion cycle.

A synchronous dynamometer assembly for applying a load to an engine during at least one portion of the combustion cycle of the engine in a synchronised manner so as to be repeatable each cycle of the engine comprises a dynamometer having a non-inductive load which is applied to the engine during operation to vary the speed of the engine. The non-inductive load is variable by varying the current delivered to it. Crankshaft monitoring means monitors the rotational position of the engine crankshaft, and combustion detection means detects a combustion event in a cylinder of the engine. Control means is operatively connected to the dynamometer for applying the load from the dynamometer to the engine for at least one part of the combustion cycle in real time such that the different loads may be applied to the engine for different parts of the combustion cycle.

Systems and methods for operating a driveline of a hybrid vehicle are described. In one example, a torque of an engine is adjusted in response to an error between an actual electric machine torque and a minimum electric machine torque plus an offset torque. The reduction of engine torque may be performed when a driveline is operating in a speed control mode.

Methods and systems are provided for detecting cylinder-to-cylinder air-fuel ratio (AFR) imbalance in engine cylinders. In one example, a method may include detecting an AFR imbalance of an engine cylinder based on an individual crankshaft acceleration of the cylinder relative to a mean crankshaft acceleration produced by all cylinders of the engine, and correcting a fuel amount of the cylinder via a fuel multiplier value, the fuel multiplier value selected from a plurality of fuel multiplier values based on an imbalance source. In this way, the AFR imbalance may be accurately detected and correcting using existing engine system sensors.

A method includes receiving information indicative of a temperature of exhaust gas emitted from an engine operating at an engine speed, determining that the temperature of the exhaust gas is below a predefined temperature threshold, determining an engine load sized to increase the temperature of the exhaust gas above the predefined temperature threshold, increasing a load on the engine to the determined engine load while maintaining the engine at the engine speed by increasing at least one of a fuel flow rate and a fuel flow pressure of the fuel pump powered by the engine, and diverting the excess fuel from the fuel flow path upstream of the engine. Increasing at least one of the fuel flow rate and the fuel pressure of the fuel pump causes excess fuel to be provided to the engine than is necessary to maintain the engine at the engine speed.

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; ignition timing detector detecting ignition timing of fuel in combustion chamber; and controller including CPU and memory. Controller performs: determining whether fuel has been supplied into fuel tank; determining whether reforming is needed based on ignition timing when it is determined that fuel has been supplied; controlling operation of reform unit so as to reform fuel stored in fuel tank to supply to injector when it is determined that reforming is needed; and controlling operation of reform unit so as to supply fuel stored in fuel tank to injector without reforming when it is determined that reforming is not needed.