An inter-connect circuit (ICC) device for a fuel delivery system of a vehicle is disposed between an engine control unit (ECU) and a fuel control device. The ECU transmits a drive pulse to the fuel control device by way of a drive pulse line passing through the ICC device. The ICC device includes a housing and a sense circuit. The housing has a first side that is connectable to the ECU and a second side different from the first side that is connectable to the fuel control device. The sense circuit is disposed within the housing. The sense circuit is electrically coupled to the drive pulse line by way of a sense circuit line and is communicably coupled to the ECU by way of a data communication line.

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 fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. 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.

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 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.

Methods and systems are provided for improving the performance of a variable displacement engine. Split injection and spark retard may be used in active cylinder during a VDE mode to heat an exhaust catalyst and extend the duration of VDE mode operation. Split injection and spark retard may also be used in reactivated cylinders at a time of cylinder reactivation to improve restart combustion stability.

An engine control system includes first and second control modules. The first control module determines a fuel combustion parameter. The second control module determines a fuel delivery parameter based on the fuel combustion parameter. The fuel combustion parameter includes at least one of (i) a total amount of heat released by a volume of fuel during a combustion cycle and (ii) a rate at which heat is released during the combustion cycle. The fuel delivery parameter includes at least one of (i) a duration of time over which the volume of fuel is delivered to a cylinder, (ii) a time at which a fuel injector starts delivering the volume of fuel to the cylinder, and (iii) a fuel pressure in a fuel rail.

A method for starting a direct-injection internal combustion engine of a vehicle includes: rotating the high-pressure injection pump by a starter; measuring fuel pressure delivered by the pump, taken at two successive compression top dead centers of the pump operating in maximum output mode; establishing the pressure gradient of the fuel, on an angular reference system, based on the two successive pressure measurements; comparing the established gradient with a predefined bijective table that respectively matches a plurality of quantities of fuel to be injected and a plurality of pressure gradients; and adapting the quantity of fuel injected during the starting phase before the engine reaches steady operating speed, depending on the result of the comparison, in order to inject a quantity of fuel that corresponds, in the predefined bijective table, to the established pressure gradient, upon authorization of the first injection given by the engine control unit.

A vehicle control system for an internal combustion engine having a fuel injection valve for injecting fuel directly into a combustion chamber includes a controller configured to perform a fuel cut-off when a predetermined fuel cut-off condition is met during travel of the vehicle to thereby stop fuel injection from the fuel injection valve. The controller is configured to resume the fuel injection from the fuel injection valve when a predetermined fuel cut-off recovery condition is met during the fuel cut-off. The controller is configured, upon elapse of a predetermined time that is required for a wall temperature of the combustion chamber to rise after resuming the fuel injection from the fuel injection valve, to perform a rich spike that temporarily increases the fuel injection amount from the fuel injection valve.