Abstract: The invention relates to a method for determining the ignitability of fuel, particularly of diesel, biodiesel, gas-to-liquid or biomass-to-liquid fuel, with an unknown fuel quality for an internal combustion engine. Provision is made for the density of the fuel to be ascertained and for the ignitability to be derived from this.

Abstract: The injector comprises a balanced metering servovalve for controlling a rod for opening/closing a nebulizer. The servovalve has a valve body having a control chamber provided with an outlet passage that is opened/closed by an axially mobile open/close element. The open/close element is made of a single piece with a bushing separate from an armature plate of an electromagnet. The bushing is coupled to a stem in an axially slidable way for closing an exhaust duct in communication with the outlet passage The open/close element is kept in a closed position by a spring that acts upon the bushing through an intermediate body connected thereto. The armature plate can be displaced with respect to the bushing between a flange of the intermediate body and a shoulder of the bushing, for eliminating the rebounds of the open/close element upon closing of the servovalve.

Abstract: The present invention realizes an injector drive circuit capable of providing high output power of a boost convertor while suppressing increases in size and cost thereof. An injector energizing circuit 200 includes an FET 2 which applies a high voltage 100a generated by a boost convertor 100 to an injection valve 20. The boost convertor 100 includes an input side capacitor 103, a boosting FET 105, a boost coil 104, a boost diode 106, and FETs 108 and 109 provided in association with a negative pole of an output side capacitor 107. During a period in which the high voltage 100a is applied to the injection valve 20, a gate signal 108a of the FET 108 is turned ON and a gate signal 109a of the FET 109 is turned OFF. Consequently, the boosting FET 105 performs a switching operation to turn OFF the gate signal 108a of the FET 108 and turn ON the gate signal 109a of the FET 109 during a period for charging into the output side capacitor 107.

Abstract: An accurate control of a solenoid-operated fuel injector in a Diesel or gasoline engine specifies that a pull-in voltage (Vpull-in) higher than the generally available battery voltage (Vbatt) is applied to the injector, and that the injection is ended as quickly as possible, in order that the fuel injection closely follows the solenoid current profile. When the initial pull-in voltage is lower than the expected nominal value, a deviation of the injected fuel quantity appears with respect to the nominal quantity. This inconvenience is overcome by monitoring the actual value of a selected parameter, such as the actual value of the initial pull-in voltage (Vpull-in), and the injection start time (te) and the solenoid energizing time (ET) are correspondingly modified.

Abstract: A sealing arrangement of a piezoactuator (12) for a fuel injection valve of an internal combustion engine, has connecting pins (14) projecting out of the piezoactuator (12) and a head arrangement (16, 18) placed on to the piezoactuator (12), which is provided with openings (20) for the penetration of the connecting pins (14), wherein a liquid-tight sealing element (30) abuts against the outer surfaces of the connecting pins (14) on one side and also against the head arrangement (16, 18) on the other. In order to ensure a reliable seal with this arrangement, in particular also over extended periods of time, the sealing element (30) abuts against the outer surfaces of the connecting pins (14) located inside the openings (20), and sealing element sections (32) located inside the openings (20) are radially compressed in the openings.

Abstract: The present invention provides a fuel injector, comprising a housing having a sealable injector seat; a fuel injector pin disposed within the housing proximate) the injector seat such that the injector seat may be sealed and unsealed by displacing the fuel injector pin; a resilient element biasing the fuel injector pin in an unsealed direction; a piezoelectric actuator disposed within the housing proximal to the fuel injector pin configured to actuate to force the injector pin towards the injector seat to seal the injector seat; and a thermal compensating unit disposed within the housing proximal to the actuator and configured to compensate for thermal expansion or contraction of a component of the fuel injector.

Abstract: A fuel injection arrangement for a piston engine, the arrangement comprising an injector nozzle (1) for injecting fuel into the combustion chamber (6) of the cylinder. A Theological actuator (15) is arranged in connection with the injector nozzle (1), the actuator comprising a space (18) containing Theological fluid and an apparatus (19, 20) by means of which the viscosity of the Theological fluid can be changed for controlling the fuel injection.

Abstract: The operation of a fuel injector for an internal combustion engine is controlled, wherein the fuel injector has an on time that includes a pull-in time during which injector current increases to a pull-in current followed by a hold time during which the injector current is limited to a hold current that is less than the pull-in current. A control circuit receives a pressure signal from a pressure sensor that corresponds to a pressure of fuel supplied to the fuel injector for injection into the engine, correlates the pressure signal with fuel pressure, and decreases the pull-in time with increasing fuel pressure.

Abstract: The injector comprises a metering servo valve for controlling a rod for opening/closing a nebulizer. The servo valve has a valve body having a control chamber provided with an outlet passage that is opened/closed by an open/close element that is axially movable. The open/close element is separate from an armature of an electromagnet, and is slidable on an axial guide element for closing the outlet passage. The open/close element is held in the closing position by a spring acting through an intermediate body. The armature can be displaced with respect to the axial guide element between a flange of the intermediate body and a projection element of the guide member, for eliminating the rebounds of the open/close element upon closing of the solenoid valve.

Abstract: A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine. A fuel supply line enters an injector housing from a high-pressure fuel source which can be hydraulically connected to a pressure chamber. A 3/2 directional control valve for injecting fuel into the combustion chamber has a valve piston which can be moved axially back and forth between a rest position and an injection position. The 3/2 directional control valve, by a first end face of the valve piston, is hydraulically coupled to and can be activated by a piezoelectric actuator. The 3/2 directional control has a ball element which is connected to a second end face of the valve piston and, in the rest position, can be moved against a first sealing edge and, in the injection position, can be moved against a second sealing edge.

Abstract: A fuel injector is disclosed. The fuel injector includes an injector valve needle and a valve actuation assembly including a stator, an armature, and a valve, the valve in fluid communication with the injector valve needle. A stator protection device is positioned between the stator and at least a portion of the armature. The stator protection device is configured to prevent contact between the stator and the armature.

Abstract: A coloring apparatus 1 includes a coloring nozzle 31 for spouting a coloring material, a signal generator 53, and a controller 19. The coloring nozzle 31 includes an electromagnetic valve 51. The signal generator 53 outputs signals for spouting the coloring material from the coloring nozzle 31 to both a CPU 62 of the controller 19 and a driving circuit 64. The CPU 62 outputs a signal for keeping the electromagnetic valve 51 open to the driving circuit 64 when a frequency of the signals from the signal generator 53 is higher than a specific frequency. When at least one of the signals from the CPU 62 and the signal generator 53 is inputted, the driving circuit 64 applies a spike voltage A and then applies a hold voltage B to a coil 40. While at least one of the signals from the CPU 62 and the signal generator 53 is inputted, the driving circuit 64 applies a spike voltage A and then continuously applies a hold voltage B to a coil 40.

Abstract: An electromagnetically actuable valve, e.g., a fuel injector for fuel-injection systems of internal combustion engines, includes an electromagnetically actuable actuating element having a solenoid coil, a fixed core, a valve jacket, and a movable armature for actuating a valve-closure element, which cooperates with a valve-seat surface provided on a valve-seat body. A sleeve-shaped guide element is introduced into an inner longitudinal bore of the armature and into an inner flow bore of the internal pole, the guide element being firmly fixed in place in the armature or the inner pole, and loosely guided in the respective other component.

Abstract: A fuel injection control apparatus for an internal combustion engine which can inject a fuel injection quantity to a fuel injector with accuracy even when the fuel injection quantity is reduced than before is provided.

Abstract: A fuel injector for an internal combustion engine is provided. The fuel injector is to be installed in a cylinder head of the engine and has a fuel pressure sensor working to measure the pressure of fuel within a injector body. The fuel pressure sensor is installed in a portion of the injector body which is to be located away from the cylinder head of the engine across a portion of the injector body on which a mechanical pressure is exerted by an external member such as a fuel supply pipe or a fuel drain pipe, thereby keeping the fuel pressure sensor free from internal stress, as arising from the mechanical pressure exerted on the injector body, to ensure the accuracy in measuring the pressure of the fuel.

Abstract: A fuel injection system includes an injector control module, a current detection module, and a position determination module. The injector control module controls current through a solenoid of a fuel injector for a predetermined period. The current detection module measures an amount of current through the solenoid after the predetermined period. The position determination module determines whether the fuel injector injected fuel during the predetermined period based on when the amount of current through the solenoid is less than or equal to a predetermined current.

Abstract: A controller moves a solenoid operated valve with a first solenoid operating pulse during a travel time. After a time interval, the controller applies a second pulse, which moves the valve towards its original position. The time interval may be varied, and a characteristic indicative of the return of the valve to the original position may be detected based on a comparison of the pulses.

Abstract: A fuel injector for delivering fuel to an engine in which a housing of the injector has an internal fuel chamber and at least one exhaust port in fluid communication with the fuel chamber. A valve member is moveable relative to the housing between a closed position in which fuel within the fuel chamber is inhibited against exhaustion from the housing, and an open position in which fuel is exhaustable from the housing. An ultrasonic waveguide is separate from the housing and valve member. The ultrasonic waveguide is elongate and has longitudinally opposite ends. The waveguide further has a first waveguide segment and a second waveguide segment. The first and second segments are disposed entirely within the fuel chamber of the housing. An excitation device is operable in the open position of the valve member to ultrasonically excite the ultrasonic waveguide.

Abstract: An engine control unit for controlling an automobile engine, which is equipped with a booster circuit for boosting the voltage of battery power source, an injector driving circuit for driving an injector by making use of a boosted high voltage, and a microcomputer for controlling the engine; wherein the engine control unit is featured in that an LC module mounted with a booster coil constituting the booster circuit and with an electrolytic capacitor, a power module mounted with a rectifying device constituting the booster circuit and the injector driving circuit and with a switching device, and a control circuit board mounted with the microcomputer and with a connector acting as an interface for an external member of the engine control unit are laminated each other.

Abstract: The present disclosure is directed to integrated injector/igniters providing efficient injection, ignition, and complete combustion of various types of fuels. One example of such an injectors/igniter can include a body having a base portion opposite a nozzle portion. The base portion receives the fuel into the body and the nozzle portion can be positioned adjacent to the combustion chamber. The injector further includes a valve carried by the nozzle portion that is movable between a closed position and an open position to inject the fuel into the combustion chamber. An actuator is coupled the valve and extends longitudinally through the body towards the base portion, and a driver is carried by the body and is movable between a first position and a second position. Thermochemical regeneration of waste heat produced by combustion and associated combustion events is captured and invested in endothermic reactions to improve efficiency of the combustion event.

Abstract: A fuel injection system includes an injector control module, a current detection module, and a position determination module. The injector control module controls current through a solenoid of a fuel injector for a predetermined period. The current detection module measures an amount of current through the solenoid after the predetermined period. The position determination module determines whether the fuel injector injected fuel during the predetermined period based on when the amount of current through the solenoid is less than or equal to a predetermined current.

Abstract: The present invention provides an injector-ignition fuel injector for an internal combustion engine, comprising an input fuel metering system for dispensing a next fuel charge into a pressurizing chamber, a pressurization ram system including a pressurization ram for compressing the fuel charge within the pressurizing chamber, wherein the fuel charge is heated in the pressurization chamber in the presence of a catalyst, and an injector nozzle for injecting the heated catalyzed fuel charge into a combustion chamber of the internal combustion engine.

Abstract: A fuel injection device and associated method are provided. An injector body defines an axial bore and has a nozzle exit extending into the combustion chamber. The injector body receives fuel within the bore and channels the fuel through the nozzle exit into the combustion chamber. A flow rate control member is movably disposed within the injector body bore and is actuatable by a first actuator to move with respect to and to interact with the nozzle exit to control a flow rate of the channeled fuel. A pintle member is movably disposed within a flow rate control member bore and is actuatable by a second actuator, independently of the flow rate control member, to move with respect to the flow rate control member and to interact with the nozzle exit to control a spray angle of the channeled fuel. The flow rate and spray angle are thereby independently controllable.

Abstract: A method for controlling the displacement of a stack of a piezoelectric actuator for use in a fuel injector comprises determining a desired amount of charge (?Q) to be added or removed from the stack. The method further comprises determining an operating parameter of the fuel system and selecting a drive current level (PO, SO) and a drive time (topen, tclose) in accordance with the desired amount of charge (?Q) and the operating parameter, and driving the drive current through the stack for the drive time (topen, tclose) in order to add or remove the desired amount of charge (?Q).

Abstract: A method for controlling a DI fuel injector relying on measurement of a engine operating parameter, preferably fuel pressure in an associated fuel rail. Regimes of low fuel injector flow require lowered fuel rail pressure, allowing lowered peak and hold currents that afford quicker closing. Under low flow conditions, a prior art fixed peak current exceeds the current required for rapid opening of the fuel injector, and a prior art fixed hold current exceeds the current required for holding the valve open for the full duration of the open window. In the present invention, the peak and hold currents, and optionally peak and hold voltages, are varied as functions of fuel rail pressure, either continuously or stepwise. The result is full function of a fuel injector over the full range of fuel flow requirements while also providing the quickest possible response under all flow conditions.

Abstract: Disclosed are a method and a device for more rapidly switching inductive fuel injection valves. According to the invention, the magnetic retaining forces generated by remanence in a bistable valve comprising an opening and closing coil or by eddy currents in a standard valve comprising an opening coil and a closing spring are eliminated with the aid of a negative current that flows through the coil in a direction running counter to the direction of the operating current. Additionally, the magnetic yoke and armature that are used are made of materials having different conductivities in order to be able to close the valve even more quickly.

Abstract: An engine control system includes a driver module and a diagnostics module. The driver module includes a high-side driver and a low-side driver, which selectively actuate a load. The driver module generates status signals based on detection of each of a plurality of failure modes of the high-side and low-side drivers. The diagnostics module increments a first error count for a first mode of the plurality of failure modes when the status signals indicate the driver module has detected the first mode. The diagnostics module increments a corresponding total count each time the driver module analyzes the first mode. The diagnostics module sets a fail state for a diagnostic trouble code (DTC) when the first error count for the first mode reaches a first predetermined threshold prior to the total count reaching a second predetermined threshold.

Abstract: An engine control system includes a driver module and a diagnostics module. The driver module includes a high-side driver and a low-side driver, which selectively actuate a load. The driver module generates status signals based on detection of each of a plurality of failure modes of the high-side and low-side drivers. The diagnostics module increments a first error count for a first mode of the plurality of failure modes when the status signals indicate the driver module has detected the first mode. The diagnostics module increments a corresponding total count each time the driver module analyzes the first mode. The diagnostics module sets a fail state for a diagnostic trouble code (DTC) when the first error count for the first mode reaches a first predetermined threshold prior to the total count reaching a second predetermined threshold.

Abstract: There is provided an internal combustion engine controller that realizes a reduction in maximum current value and current regulation without sacrificing boost performance.

Abstract: With reference to FIG. 1, the present invention provides an internal combustion engine (10) comprising a variable volume combustion chamber (13); an air intake system (18,20,21) for delivering charge air to the combustion chamber (13); an exhaust system (17) for relaying combusted gas from the combustion chamber (13) to atmosphere; and a fuel injection system (19, 21, 22, 23, 24, 25, 26) for delivering fuel into the charge air for combustion therewith in the combustion chamber (13). The fuel injection system (19,21,22,23,24,25,26) comprises a fuel injector (19) which functions as a positive displacement pump and dispenses an amount of fuel which is fixed for each and every operation of the injector (19); and a controller (23) which controls the operation of the fuel injector (19). In. response to an increasing engine speed and/or load the controller (23) increases in amount the fuel delivered per engine cycle by increasing in number the occasions the fuel injector (19) is operated per engine cycle.

Abstract: A charging circuit for a fuel injection coil enables the controller to selectively add a pulse of increased amplitude to the beginning of an injection current pulse. Optionally, the controller can also select one of a plurality of amplitudes for the pulse and control the duration of the pulse.

Abstract: A fuel injection control apparatus is capable of reducing a minimum quantity of fuel injection without reducing a maximum quantity of injection. To open a fuel injector valve, a driving circuit supplies an electric current from a high-voltage power supply to the fuel injector. Then, after valve opening, the high-voltage power supply is switched to a low-voltage power supply, and an open state of the valve is retained. For opening the valve of the fuel injector, a microcomputer, after supplying current from the high-voltage power supply to the injector, discharges the current rapidly for a decrease below a first current level at which the open state of the valve cannot be retained. The microcomputer then controls the supply current to the injector so as to supply a current at a second current level at which the open state of the valve can be retained.

Abstract: There is proposed a control unit for an internal combustion engine, which comprises a boost circuit, a switching element, a current detecting resistor and a controller and is designed to be actuated such that the boost circuit is used to boost a power source voltage to create a boosted voltage and the controller is used to control the switching element so as to enable the boosted voltage to flow to the injector solenoid coil. This control unit is designed such that, when the boost circuit goes out of order, the injector solenoid coil is excited by making use of the power source voltage without using the boosted voltage and without creating a peak current to thereby generate a first holding current required for opening the injector and a second holding current required for retaining the opened state of the injector, the second holding current being lower in intensity than the first holding current.

Abstract: An electromagnetic fuel injection valve device for an internal combustion engine is configured to carry out an energization to an electromagnetic coil of an injection valve actuator for a valve opening motion and additionally carry out a mid-term energization at a time interval between both an energization for valve opening of a previous fuel injection and an energization for valve opening of a subsequent fuel injection. A current of the mid-term energization is smaller than a current of the energization for valve opening motion and has the same direction as a direction of the current of the energization for valve opening motion.

Abstract: A reduced cost dual fuel injection system and method is described. Port fuel injectors and direct fuel injectors may be operated by using common injector drivers.

Abstract: An apparatus is described for actuating at least one piezoelectric actuating drive (1) of an injection nozzle for an internal combustion engine, comprising a control device (6) which cyclically actuates a charging circuit and a discharging circuit (2, 3) of the piezoelectric actuating drive (1).

Abstract: A fuel injection device includes a fuel injection valve for injecting fuel, which is distributed from a pressure-accumulation vessel. A pressure sensor is located in a fuel passage, which extends from the pressure-accumulation vessel to a nozzle hole, and configured to detect pressure of the fuel. The pressure sensor is located closer to the nozzle hole than the pressure-accumulation vessel. A storage unit stores individual difference information, which indicates an injection characteristic of the fuel injection valve, the injection characteristic being obtained by an examination. The individual difference information is related to a fluctuation pattern of a portion of the fluctuation in detected pressure waveform of the pressure sensor. The fluctuation is attributed to one fuel injection through the nozzle hole. The portion of the fluctuation is subsequent to an end of the fuel injection.

Abstract: The present invention provides a fuel injector, comprising a housing having a sealable injector seat; a fuel injector pin disposed within the housing proximate to the injector seat such that the injector seat may be sealed and unsealed by displacing the fuel injector pin; a resilient element biasing the fuel injector pin in an unsealed direction; a piezoelectric actuator disposed within the housing proximal to the fuel injector pin configured to actuate to force the injector pin towards the injector seat to seal the injector seat; and a thermal compensating unit disposed within the housing proximal to the actuator and configured to compensate for thermal expansion or contraction of a component of the fuel injector.

Abstract: A fuel injection system (1) for the targeted injection of fuel, comprising a fuel injection valve (2) having a solenoid coil (3), which cooperates with an armature (5) supplied by a return spring (4), the armature forming an axially displaceable valve part together with a valve needle (6), and a control device (9). The control device (9) defines an opening phase (10) having a first holding current (12), and a closing phase (11) beginning after the opening phase (10) and having a second holding current (13) for the fuel injection valve (2), wherein the current characteristic in the solenoid coil (3) is defined during the closing phase (11) of the injection valve (2) such that the magnetic field generated by the second holding current (13) flowing through the solenoid coil (3) brings about a certain magnetic force, such that the valve needle (6) thus experiences a defined stroke (14) that is different from zero, and steadily maintains the same over a defined period of time.

Abstract: A device for controlling at least one piezoactuator for an injection valve of an internal combustion engine, including a microcontroller that controls an output stage which generates the load current for charging and discharging the piezoactuator. The microcontroller controls the output stage through an integrated circuit. A discharge circuit interacts with the integrated circuit to reliably discharge the piezoactuator in case of a failure of the output stage and/or of a safety path of the microcontroller. The load current during the discharge is controlled by a control circuit having a controller which is part of the integrated circuit. The discharge circuit has emergency discharge elements that are activated in case of a failure of the controller or of the integrated circuit.

Abstract: An engine control system comprises a current control module and a solenoid actuator module. The current control module determines a duty cycle based on a desired current through a solenoid of an engine system and a resistance of the solenoid and corrects the resistance based on an actual current through the solenoid. The solenoid actuator module actuates the solenoid based on the duty cycle.

Abstract: In a method for operating an injection valve, in particular a fuel injector of an internal combustion engine of a motor vehicle, one component of the injection valve, particularly a valve needle, is disposed in a manner allowing movement relative to other components of the injection valve, and preferably is able to be driven at least partially by an actuator. A structure-borne-noise signal is detected by a structure-borne-noise sensor, and the structure-borne-noise signal is evaluated in order to infer an operating state of the movably disposed component.

Abstract: An electric circuit for triggering a piezoelectric element, a fuel injection system of a motor vehicle in particular, is described. A first measuring shunt connected in series to the piezoelectric element is provided. Provided are two transistors connected in series whose shared connecting point is connected to the piezoelectric element. A second measuring shunt is also provided. The two transistors and the second measuring shunt are connected in series.

Abstract: A controller for controlling the operation of a fuel injector having a piezoelectric actuator which is operable by the application of a voltage drive profile across the actuator, the controller comprising inputs for receiving data relating to one or more engine parameters and a processor for determining a voltage drive profile for controlling the actuator in dependence upon the one or more engine parameters. The voltage drive profile is arranged to comprise an activating voltage component to initiate an injection event and a deactivating voltage component to terminate the injection event, the activating and deactivating voltage components being separated by a time interval TON. The controller further receives outputs for outputting the voltage drive profile as determined by the processor to the actuator, wherein the processor is arranged to set the time interval TON greater than or equal to a predetermined pressure wave time period (TP) of a pressure wave cycle within the injector.

Abstract: A method for improving fuel heating is presented. The method can reduce system complexity and cost when fuel is heated within a fuel injector. In one embodiment, the method independently heats and injects fuel by changing the direction of current flow through a fuel circuit.

Abstract: A method is for operating an injector, in particular a fuel injector of an internal combustion engine in a motor vehicle, the injector having a piezoelectric actuator for driving a valve needle coupled, preferably hydraulically, to the actuator. Starting from a starting voltage corresponding to a first operating state of the injector, the actuator is recharged, i.e., charged or discharged, by a predefinable voltage swing to a target voltage corresponding to a second operating state of the injector.

Abstract: A circuit arrangement for operating at least one inductive load, for example a solenoid of a fuel injection valve, is configured to feed back electrical energy into a storage capacitor in a freewheeling phase after driving the load. In order to avoid an unwanted voltage increase on the capacitor, the circuit arrangement includes a DC/DC converter with the output-side storage capacitor to provide an operating voltage for the load. A drivable circuit arrangement optionally connects the load to the capacitor, and a freewheeling diode arrangement feeds back electrical energy into the capacitor after the circuit arrangement has been switched off. A protection circuit, which is connected in parallel with the capacitor, provides a current path for limiting the charging voltage on the capacitor in the event of an excessively high voltage on the capacitor.

Abstract: Disclosed is a fuel injection apparatus comprising a solenoid coil (40); an armature (41) coupled with a valve element (34) operable to open and close a fuel valve (32) when the solenoid coil (40) is selectively energized and de-energised with (current, the valve element (34) being biased to the closed position by a biasing means (42); and a control means (170) wherein the control means (170) energises the solenoid coil (40) to cause a magnetic force to move the armature (41) and valve element (34) to open the valve to an opening position to deliver fuel, the opening position being reached when the control means (170) calculates that forces urging opening of the valve balance with forces urging closure of the valve. Such control over opening position may be used to control fuel flow rate to a gas fuelled engine (20) and/or reduce noise vibration harshness in varied engirie types.

Abstract: A control arrangement for a fuel injection apparatus of an internal combustion engine, the fuel injection apparatus comprising at lest two fuel injector nozzles, the injection action of which is controllable via a solenoid, and at least two control units arranged to control the solenoids controlling the injection action. According to the invention, each injector nozzle is provided with a first and second solenoid and the first and second solenoid are in connection with a different control unit.

Abstract: A direct fuel injection control for an internal combustion engine includes first and second controllers. The first controller has a microprocessor and generates injection timing and duration signals on injector select lines. The second controller is a state machine including injector controls that receive the injection timing and duration signals and control injector current according to sets of injector current profile defining parameters received from the first controller on a serial bus and stored in register sets in the second controller. The second controller includes switching apparatus that can quickly change the connection of each injector control between different register sets to select different injector current profiles in successive injection pulses. Several alternative ways of providing register select signals are disclosed, and these may be incorporated in the same second controller for selection by the first controller.