Various methods are provided for managing a fuel system of a vehicle. In one example, the method may include enclosing, at least partially, a gaseous fuel delivery, storage, and/or consumption element of the vehicle. The method may include sensing an indication of gaseous fuel in an unintended region and generating an alert and/or adjusting an actuator in response to the sensed gaseous fuel above a threshold.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a target combustion condition. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition via a feedback control with a gain. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to determine the gain so as to increase as the fuel ratio decreases.

A control apparatus is disclosed for operating a fuel injector of an internal combustion engine. The control apparatus includes an Electronic Control Unit configured to: perform a first calculation task in order to calculate a set of Start Of Injection values (SOI.sub.i) of a train of injections, calculate an angular position (DIAngPos) of the crankshaft defining the start of a second calculation task, and perform the second calculation task in order to calculate a set of values (ET.sub.i) of the energizing time of the injections of the train. The angular position (DIAngPos) is calculated as a function of the Start Of Injection value (FirstSOI) of the first injection of the train as calculated by the first calculation task.

A method of determining the timing and quantity of fuel injection to operate an internal combustion engine is disclosed. While operating the fuel injector to perform a fuel injection; a signal of a fuel pressure within the fuel rail during the fuel injection is sampled. The signal is used to determine first and second integral transforms yielding as output a value of first and second functions having as variables the fuel rail pressure drop caused by the fuel injection and the timing parameter indicative of the instant when the fuel injection started. Values of the first and second functions are used to calculate a value of the fuel rail pressure drop caused by the fuel injection and a value of the timing parameter. A value of a fuel quantity injected by the fuel injection is calculated as a function of the value of the fuel rail pressure drop.

A method for operating an internal combustion engine, the method including the steps of: (a) actuating an injector to introduce a pre-injection amount of a fuel into a combustion chamber of the internal combustion engine; (b) determining, for an operating cycle of the combustion chamber in which the injector was actuated in the step (a), a pressure gradient characteristic value which is characteristic of a combustion chamber pressure gradient in the combustion chamber; (c) repeating the steps (a) and (b) a plurality of times; (d) determining a skew of a distribution of a plurality of pressure gradient characteristic values determined in the step (c); and (e) changing or maintaining an actuation of the injector depending on the skew determined in the step (d).

A fuel estimation apparatus includes a combustion characteristic acquisition portion and a mixing ratio estimation portion. The combustion characteristic acquisition portion acquiring a combustion characteristic value indicating a physical amount relating to a combustion of an internal combustion engine acquires the combustion characteristic values of the combustions executed in different combustion conditions. The mixing ratio estimation portion estimates the mixing ratios of various components included in a fuel, based on the combustion characteristic values acquired by the combustion characteristic acquisition portion.

A vehicle includes a residual pressure holding valve provided downstream a feed pump of a fuel to hold a pressure in a fuel pipe leading to the port injection valve. Residual pressure holding valve is opened to return the fuel in the fuel pipe to the fuel tank when the pressure in the fuel pipe exceeds a valve opening pressure, and closed when the pressure in the fuel pipe is lower than the valve opening pressure. At the time of a request to reduce a target pressure of the fuel to be supplied to the electric feed pump, a control device refrains from causing the target pressure to decrease when a load of the engine is smaller than a prescribed value, and causes the target pressure to decrease when the load of the engine is greater than the prescribed value.

Methods and systems are provided for detecting a temperature of an engine fuel rail at a plurality of locations along the engine fuel rail. In one example, a method may include detecting temperatures along the engine fuel rail with a plurality of metal film thermocouples adhered to the engine fuel rail and arranged proximate to engine fuel injectors, and adjusting fuel injector operation and/or fuel rail pressure in response to the detected fuel rail temperatures.

The invented system adds some petrol fuel to the vehicle engine which runs with natural gas (CNG or LPG). It causes a simultaneous combustion of petrol and natural gas (CNG or LPG). This action decreases depreciation of engine, increases power of the engine and reduces fuel consumption in natural gas vehicles. The above-mentioned system consists of an innovative petrol holder storage, an electronically circuit, a relay, a lever micro switch and a petrol fuel injector. Whenever the accelerator pedal is pressed more than a certain amount, the system will be activated and command to inject petrol collected in the storage into the air manifold.

Methods and systems are provided for the integration of a fuel level sensor and a fuel pressure sensor in a fuel tank within a fuel system. In one example, an integrated fuel pressure and fuel level sensor for a fuel tank may include a float arm of the fuel sensor coupled to a floating body and a pressure sensor (e.g., a fuel tank pressure transducer) coupled to the floating body, the integrated fuel pressure and fuel level sensor adapted to simultaneously measure fuel level and fuel vapor pressure of the fuel tank.