Methods and systems are provided for reducing errors in estimated fuel rail pressure incurred at the time of a scheduled injection event due to engine-driven cyclic fuel rail pressure changes. In one example, a pulse-width commanded during a scheduled injection event is determined as a function fuel rail pressure samples collected over a moving window that is customized for the corresponding fuel injector. In another example, the commanded pulse-width is determined as a function of an average fuel rail pressure sampled during a quiet zone of injector operation and predicted fuel rail pressure altering events occurring between the quiet zone and the scheduled injection event.

A control system for an engine includes one or more processors configured to determine when a change in one or more of oxygen or fuel supplied to an engine. The one or more processors also are configured to, responsive to determining the change in oxygen and/or fuel supplied to an engine, direct one or more fuel injectors of the engine to begin injecting fuel into one or more cylinders of the engine during both a first fuel injection and a second fuel injection during each cycle of a multi-stroke engine cycle of the one or more cylinders.

The invention relates to a method for producing a valve (1) that can be electromagnetically actuated which method comprises an electromagnet (2, 2a, 2b), an armature (3) that can be moved by the electromagnet (2, 2a, 2b), and a valve body (5), having means (4, 4a, 4b, 4c) for converting a movement of the armature (3) into an opening or closing of the valve (1), wherein the electromagnet (2, 2a, 2b) and the armature (3) are inserted into the valve body (5), wherein, before the electromagnet (2, 2a, 2b) is inserted into the valve body (5), a magnetic hysteresis curve (10) of a combination (6) of the electromagnet (2, 2a, 2b) having a test armature (3a) lying against said electromagnet (2, 2a, 2b) is recorded, the slope m.sub.1 of a first, substantially linear curve segment (11) of the hysteresis curve (10) is determined in the unsaturated state, and, from the slope m.sub.1, the slope m.sub.1* of a curve segment (31) of a hysteresis curve (30) of the finally assembled valve (1) having the armature (3) lying continuously against the electromagnet (2, 2a, 2b) is determined, said curve segment corresponding to the first curve segment (11). The invention further relates to a method for determining the armature stroke AH, wherein the magnetic energy E in the air gap (9) formed between the armature (3) and the electromagnet (2, 2a, 2b) is evaluated from the difference between the first slope m.sub.0 and the second slope m.sub.1*.

The present invention relates to a fuel additive composition for controlling formation of deposits and for reducing already formed deposits formed in a fuel injection system and engine, or in an internal combustion engine, wherein the fuel additive composition comprises oxide derivative of (a) iso-borneol or (b) borneol, and to a method of use thereof. In one embodiment, the present invention relates to a fuel additive composition for controlling formation of deposits and for reducing already formed deposits formed in a fuel injection system and engine, or in an internal combustion engine, wherein the fuel additive composition comprises (a) iso-borneol or (b) borneol, and to a method of use thereof. In one embodiment, the present invention relates to a fuel additive composition for controlling formation of deposits and for reducing already formed deposits formed in a fuel injection system and engine, or in an internal combustion engine, wherein the fuel additive composition comprises a mixture of oxirane or an oxide compound with (a) iso-borneol or (b) borneol, and to a method of use thereof. In one embodiment, the present invention relates to a composition comprising a fuel and the fuel additive composition of the present invention.

A method for fouling an injector of a gasoline direct injection engine, includes the steps of operating the direct injection engine on at least a first stationary engine mode which is defined by a pre-established engine load and a pre-established engine speed. Both the pre-established engine load and the speed are within 35% and 65% of their maximum values, this at least first stationary engine mode being characterized by high particulate matter generation. The direct injection engine is operated on the at least first engine mode for less than ten hours.

A method for evaluating the fouling effect of a gasoline formulation in a gasoline direct injection engine uses the above-described fouling method.

A fuel injection control device has a conduction time calculation unit, a setting unit, a conduction control unit, a detection unit, an estimation unit, and a changing unit. The conduction time calculation unit calculates a conduction time of an electric actuator corresponding to a requested injection quantity during partial lift injection. The setting unit sets a command conduction time. The conduction control unit energizes an electric actuator on the basis of a command conduction time set by the setting unit. The detection unit detects a physical quantity having a correlation with an actual injection quantity during partial lift injection. The estimation unit estimates an actual injection quantity on the basis of a detection result of the detection unit. The changing unit changes a lower limit time on the basis of a deviation between an estimated actual injection quantity and a requested injection quantity.

A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.

A fuel injection apparatus for injecting fuel to an engine having cylinders, includes: injectors corresponding to the cylinders; a regulator for fuel pressure supplied to the injectors; and a processor. The processor performs: deciding to start a deposit removal for removing deposits adhering to injector-nozzles; and controlling each injector to inject fuel in a single injection mode for injecting one time or a divided injection mode for injecting multiple times in one combustion cycle and control the regulator based on engine operation condition. The controlling includes, when controlling each injector to inject fuel in the divided injection mode based on the engine operation condition, sequentially controlling each injector to reduce injection number in one combustion cycle when the deposit removal is decided to be started, and then controlling the regulator to increase fuel pressure.

Methods and systems are disclosed for operating an engine that includes fuel injectors that supply fuel to cylinders of the engine. According to the methods and system, variation of individual fuel injection amounts injected by a sole fuel injector are determined so that it may be determined if individual fuel injector variation may be contributing to engine air-fuel ratio variation.

A fuel injection control device includes a conduction time calculation unit, a detection unit, an estimation unit, a correction unit, a sudden change determination unit, and a reflection speed setting unit. The detection unit detects a physical quantity having a correlation with an actual injection quantity during the partial lift injection. The estimation unit estimates the actual injection quantity on the basis of a detection result of the detection unit. The correction unit corrects the requested injection quantity by a correction quantity corresponding to a deviation between the actual injection quantity and the requested injection quantity. The sudden change determination unit determines whether or not the correction quantity is in a sudden change state on the basis of whether or not the correction quantity has changed from a previous value by a prescribed quantity or more. The reflection speed setting unit sets the reflection speed.