AU2011282485B2 - Altering fuel usage - Google Patents

Abstract

A device and method for altering fuel usage in a multi-cylinder combustion engine of a vehicle, wherein the device includes a processing unit which is retrofittably adapted to be in electrical communication with one or more electronic components of the engine, fuel injectors of the engine, and an engine control unit of the engine. The processing unit is configured to monitor, during operation of the vehicle, one or more operating signals from the one or more electronic components and determine, based upon the one or more operating signals, if an operating condition has been satisfied; and whilst the operating condition has been satisfied: detect, from the engine control unit, a trigger signal for actuating one of the fuel injectors; and in response to detecting the trigger signal, restrict one or more of the fuel injectors from actuation in a fuel injector firing cycle.

Description

WO 2012/009767 PCT/AU2011/000933 ALTERING FUEL USAGE Technical Field The present invention relates to altering fuel usage. In one particular form, the present 5 invention relates to a device and method of altering fuel usage for an internal combustion engine. Background In a multi-cylinder combustion engine, a plurality of fuel injectors are generally actuated, 10 via an engine control unit, to inject a mixture of air and fuel which is subsequently combusted in corresponding cylinders to maintain the normal working operation of the engine. However, as the consumption and scarcity of fossil fuels continues to increase, there has been a need to optimise the efficiency of fossil fuel based engines, such as multi cylinder multi point electronic fuel injected internal combustion engines, in order to more 15 efficiently use the fuel for operation. One means which vehicle manufacturers have implemented in order to reduce the amount of fuel that is consumed in an internal combustion engine is to configure the engine control unit of the vehicle to skip the firing of a fuel injector by failing to send a trigger signal to 20 the respective fuel injector in particular conditions (i.e. high speed). However, not all vehicles include an engine control unit which is configured in such a manner and it is an extremely difficult task to reconfigure an engine control unit to perform such a task. Additionally, it is difficult for the owner of the vehicle to adjust the engine control unit to skip the firing of the engine in other conditions than those already monitored by the engine 25 control unit. Therefore, there is a need for a device and method for altering fuel usage in an internal combustion engine that overcomes or at least alleviates one or more of the above mentioned problems, or at least provides a useful commercial alternative. 30 -2 The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. Summary In one broad aspect there is provided a device for altering fuel usage in an internal combustion engine of a vehicle, wherein the device includes a processing unit which is retrofittably adapted to be in electrical communication with: one or more electronic components of the engine; fuel injectors of the engine; and an engine control unit of the engine; wherein the processing unit is configured to: monitoring, during operation of the vehicle, one or more operating signals of the one or more electronic components; determine, based upon the one or more operating signals, if an operating condition has been satisfied; and whilst the operating condition has been satisfied: detect, from the engine control unit, a trigger signal for actuating one of the fuel injectors; and in response to detecting the trigger signal, restrict one or more of the fuel injectors from actuation in a fuel injector firing cycle wherein the device includes a mode input unit for selectively operating the device in an initialisation mode, wherein upon selection of the initialisation mode, the processing unit monitors, and stores in memory of the processing unit, one or more operating parameters of the vehicle at a low load operating state for use in determining if the operating condition has been satisfied. In one form, the processing unit is configured to cyclically progress through the plurality of injectors for restriction over multiple fuel injector firing cycles.

-3 In another form, the processing unit restricts the one or more injectors from actuation by creating an open circuit between a power source and the respective one or more injectors. In one embodiment, the device includes a plurality of switching units, each switching unit being in electrical communication with the power source, a respective fuel injector and the processing unit, wherein the processing unit electrically actuates one of the switching units to restrict the actuation of the respective fuel injector. In another embodiment, the device includes a selectively operable current source in electrical communication with the processing unit and the engine control unit, wherein when one of the fuel injectors is restricted, the current source provides an electrical signal to the engine control unit, thereby simulating that the respective fuel injector has actuated. In an optional form, the device includes a plurality of current sources corresponding to the plurality of fuel injectors, wherein each current source is configured to simulate actuation of a respective fuel injector. In another optional embodiment, the mode input unit is operable for selecting: an active mode, wherein the processing unit detects if the operating condition has been satisfied and in response restricts one or more of the fuel injectors; or an inactive mode, wherein the fuel injectors operate uninhibitedly. In one form, the processing unit includes memory which stores therein sequence data indicative of an injector restriction sequence defining an order which the fuel injectors are to be restricted when the operating condition has been satisfied, wherein the processing WO 2012/009767 PCT/AU2011/000933 -4 unit is configured to retrieve and restrict one or more of the fuel injectors, in accordance with the sequence data, when the operating condition is satisfied. In another form, the memory stores therein a plurality of injector restriction sequences, 5 wherein the device includes a sequence input unit to select one of the injector sequences to be applied when the operating condition has been satisfied. In one embodiment, the one or more operating signals includes at least one of: a throttle signal indicative of at least one of: 10 actuation of a throttle of the engine; and a position of the throttle; a velocity signal indicative of at least one of: the vehicle undergoing motion; and a velocity of the vehicle; 15 a temperature signal indicative of a temperature of the engine; a reverse gear signal indicative of the vehicle being in reverse gear; a manifold absolute pressure (MAP) signal indicative of a manifold absolute pressure; a mass air flow (MAF) signal indicative of a mass of air flow entering the engine; 20 an auxiliary power consumption signal indicative of an auxiliary power consuming unit being actuated; a cruise control signal indicative of an actuation of a cruise control mode for the vehicle; and an ignition signal indicative of a state of an ignition unit of the engine. 25 In another embodiment, the operating condition has been satisfied, the processing unit is configured to determine, based on the velocity signal, an operating state of the engine, wherein: whilst the velocity signal is indicative of the vehicle failing to satisfy a velocity 30 threshold, the processing unit restricts a single fuel injector in one or more fuel injector firing cycles; and WO 2012/009767 PCT/AU2011/000933 -5 whilst the velocity signal is indicative of the vehicle satisfying the velocity threshold, the processing unit restricts multiple fuel injectors from actuating in one or more fuel injector firing cycles. 5 In an optional form, the processing unit is configured to determine, based on the temperature signal, if the temperature of the engine satisfies a temperature threshold, wherein in the event that the processing unit determines that the temperature threshold is unsatisfied, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly. 10 In another optional form, the processing unit is configured to determine if the reverse gear signal indicates that the vehicle is in reverse gear, wherein in the event that the processing unit determines that the vehicle is in reverse gear, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly. 15 In an optional embodiment, the processing unit is configured to determine, based on the auxiliary power consumption and velocity signals, if the auxiliary power consumption unit has been actuated whilst the vehicle has a velocity satisfying a velocity threshold, wherein whilst the auxiliary power consumption unit is actuating whilst the velocity threshold has 20 been satisfied, the operating condition is satisfied, otherwise the operating condition has not been satisfied thereby allowing the injectors to operate uninhibitedly. In another broad aspect there is provided a device for altering fuel usage in an internal combustion engine, wherein the device includes a processing unit configured to: 25 monitor one or more operating signals of the engine; determine, based upon one or more operating signals of the engine, if the engine satisfies an operating condition; and in the event that the operating condition is satisfied, restrict at least one of the fuel injectors from actuating in the engine. 30 -6 In another broad aspect there is provided a method for altering fuel usage in a multi-cylinder combustion engine of a vehicle, wherein the method includes use of a device having a processing unit which is retrofittably adapted to be in electrical communication with: one or more electronic components of the engine; fuel injectors of the engine; and an engine control unit of the engine; wherein the method includes, in the processing unit: monitoring, during operation of the vehicle, one or more operating signals of the one or more electronic components; determining, based upon the one or more operating signals, if an operating condition has been satisfied; and whilst the operating condition has been satisfied: detecting, from the engine control unit, a trigger signal for actuating one of the fuel injectors; and in response to detecting the trigger signal, restricting one or more of the fuel injectors from actuation in a fuel injector firing cycle wherein the device includes a mode input unit for selectively operating the device in an initialisation mode, wherein the method includes receiving input indicative of selection of the initialisation mode, wherein upon selection of the initialisation mode, the method includes the processing unit monitoring, and storing in memory of the processing unit, one or more operating parameters of the vehicle at a low load operating state for use in determining if the operating condition has been satisfied. In one form, the method includes the processing unit cyclically progressing through the plurality of injectors for restriction over multiple fuel injector firing cycles. In another form, the method includes the processing unit restricting the one or more injectors from actuation by creating an open circuit between a power source and the respective one or more injectors. In one embodiment, the device includes a plurality of switching units, each switching unit being in electrical communication with the power source, a respective fuel injector and the processing unit, wherein the method includes the processing unit electrically actuating one of the switching units to restrict the actuation of the respective fuel injector.

-7 In another embodiment, the device includes a selectively operable current source in electrical communication with the processing unit and the engine control unit, wherein when one of the fuel injectors is restricted, the method includes the current source providing an electrical signal to the engine control unit, thereby simulating that the respective fuel injector has actuated. In an optional form, the device includes a plurality of current sources corresponding to the plurality of fuel injectors, wherein the method includes each current source simulating actuation of a respective fuel injector. In an optional embodiment, the method includes receiving input indicative of a selection of: an active mode, wherein the processing unit detects if the operating condition has been satisfied and in response restricts one or more of the fuel injectors; or an inactive mode, wherein the fuel injectors operate uninhibitedly. Optionally, the processing unit includes memory which stores therein sequence data indicative of an injector restriction sequence defining an order which the fuel injectors are to be restricted when the operating condition has been satisfied, wherein the method includes the processing unit retrieving and restricting one or more of the fuel injectors, in accordance with the sequence data, when the operating condition is satisfied.

WO 2012/009767 PCT/AU2011/000933 -8 In one form, the memory stores therein a plurality of injector restriction sequences, wherein the device includes a sequence input unit to select one of the injector sequences to be applied when the operating condition has been satisfied, wherein the method includes 5 retrieving one of the injector restriction sequences, in accordance with the sequence input unit, when the operating condition is satisfied. In another form, the method includes monitoring the one or more operating signals including at least one of: 10 a throttle signal indicative of at least one of: actuation of a throttle of the engine; and a position of the throttle; a velocity signal indicative of at least one of: the vehicle undergoing motion; and 15 a velocity of the vehicle; a temperature signal indicative of a temperature of the engine; a reverse gear signal indicative of the vehicle being in reverse gear; a manifold absolute pressure (MAP) signal indicative of a manifold absolute pressure; 20 a mass air flow (MAF) signal indicative of a mass of air flow entering the engine; an auxiliary power consumption signal indicative of an auxiliary power consuming unit being actuated; a cruise control signal indicative of an actuation of a cruise control mode for the vehicle; and 25 an ignition signal indicative of a state of an ignition unit of the engine. In one embodiment, whilst the operating condition has been satisfied, the method includes the processing unit determining, based on the velocity signal, an operating state of the engine, wherein: WO 2012/009767 PCT/AU2011/000933 -9 whilst the velocity signal is indicative of the vehicle failing to satisfy a velocity threshold, the method includes the processing unit restricting a single fuel injector in one or more fuel injector firing cycles; and whilst the velocity signal is indicative of the vehicle satisfying the velocity 5 threshold, the method includes the processing unit restricting multiple fuel injectors from actuating in one or more fuel injector firing cycles. In another embodiment, the method includes the processing unit determining, based on the temperature signal, if the temperature of the engine satisfies a temperature threshold, 10 wherein in the event that the processing unit determines that the temperature threshold is unsatisfied, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly. In an optional form, the method includes the processing unit determining if the reverse 15 gear signal indicates that the vehicle is in reverse gear, wherein in the event that the processing unit determines that the vehicle is in reverse gear, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly. In another optional form, the method includes the processing unit determining, based on 20 the auxiliary power consumption and velocity signals, if the auxiliary power consumption unit has been actuated whilst the vehicle has a velocity satisfying a velocity threshold, wherein whilst the auxiliary power consumption unit is actuating whilst the velocity threshold has been satisfied, the operating condition is satisfied, otherwise the operating condition has not been satisfied thereby allowing the injectors to operate uninhibitedly. 25 In another broad aspect there is provided a method for altering fuel usage in an internal combustion engine, wherein the method includes use of a device having a processing unit, wherein the method includes, in the processing unit: monitoring one or more operating signals of the engine; 30 determining, based upon one or more operating signals of the engine, if the engine satisfies an operating condition; and WO 2012/009767 PCT/AU2011/000933 -10 in the event that the operating condition is satisfied, restricting at least one of the fuel injectors from actuating in the engine. Other embodiments will be described throughout the description of the example 5 embodiments. Brief Description of the Figures Example embodiments should become apparent from the following description, which is given by way of example only, of at least one preferred but non-limiting embodiment, 10 described in connection with the accompanying figures. Figure 1 illustrates a block diagram representing an example of a device for altering fuel usage; 15 Figure 2 illustrates a flowchart representing a method of altering fuel usage; Figure 3 illustrates a block diagram of an alternate detailed example of the device; Figure 4 illustrates a block diagram of another alternate detailed example of the device 20 including a first and second microprocessor; Figure 5 illustrates an electrical schematic representing a switching unit in electrical communication with one of the fuel injectors; 25 Figure 6 illustrates a flowchart representing a method of initialising the device of Figure 4; Figures 7A and 7B illustrate a flowchart representing a method performed by the first microprocessor of the device of Figure 4; WO 2012/009767 PCT/AU2011/000933 -11 Figure 8 illustrates a flowchart representing a method performed by the second microprocessor of the device of Figure 4 when a single fuel injector is to be restricted from actuation per fuel injector firing cycle; and 5 Figure 9 illustrates a flowchart representing a method performed by the second microprocessor of the device of Figure 4 when multiple fuel injectors are to be restricted from actuation per fuel injector firing cycle. Description of Embodiments 10 The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment. or embodiments. In the figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the figures. 15 Referring to Figure 1 there is shown a block diagram representing an example of a device for optimising the use of fuel in an internal combustion engine, preferably a multi-cylinder internal combustion engine. In one preferable form, the multi-cylinder combustion engine is a multi-cylinder multi point electronic fuel injected internal combustion engine. 20 The device I includes a processing unit 10 configured to monitor one or more operating signals 20 of the engine 70. The processing unit 10 is also configured to determine, based upon one or more operating signals 20 of the engine 70, if an operating condition has been satisfied. In the event that the operating condition has been satisfied, the processing unit 10 restricts at least one of the fuel injectors 30a-30n, generally referred to by reference 30, 25 from actuating (i.e. firing) in the engine 70. In a more specific form, the device I is retrofittable to a vehicle, generally an automobile or the like, associated with the engine 70. The processing unit 10 is retrofittably adapted to be in electrical communication with one or more electronic components of the engine, the 30 fuel injectors 30 of the engine, and an engine control unit 50 of the engine. The processing unit 10 is configured to monitor, during operation of the vehicle, the one or more operating WO 2012/009767 PCT/AU2011/000933 -12 signals 20 from the one or more electronic components and determines, based upon the one or more operating signals 20, if the operating condition has been satisfied. Whilst the operating condition has been satisfied, the processing unit 10 detects, from the engine control unit 50, a trigger signal 60a for actuating one of the fuel injectors 30a. In response 5 to detecting the trigger signal 60a, the processing unit 10 restricts one or more of the fuel injectors 30 from actuation in a fuel injector firing cycle. The device I can advantageously be retrofitted to a vehicle by an auto-electrician as the device 1 is primarily an electronic device. 10 Figure 2 also illustrates a method 200 for altering fuel usage in an internal combustion engine. In particular, at step 210, the method 200 includes the processing unit 10 monitoring, during operation of the vehicle, one or more operating signals 20 of the one or more electronic components. At step 220, the method 200 includes the processing unit 10 15 determining, based upon the one or more operating signals 20, if an operating condition has been satisfied. Whilst the operating condition has been satisfied, the method 200 continues to perform step 230 and 240. At step 230, the method 200 includes the processing unit 10 detecting, from the engine control unit 50, a trigger signal 60a for actuating one of the fuel injectors 30. At step 240, in response to detecting the trigger 20 signal 60a, the method includes the processing unit 10 restricting one or more of the fuel injectors 30 from actuation in a fuel injector firing cycle. As shown in Figure 2, the method can optionally be performed as part of a continuous loop. Generally, the operating condition is satisfied when the engine 70 is determined, by the 25 processing unit, to be under a low load. As will be discussed in more detail below, in some instances the one or more operating signals 20 may indicate to the processing unit that the vehicle is under a low load, however one or more other critical operating signals, such as the vehicle being in reverse gear or the temperature of the engine not being above a temperature threshold, can indicate that the operating condition has not been satisfied such 30 that one or more of the fuel injectors 30 are allowed to actuate freely.

WO 2012/009767 PCT/AU2011/000933 - 13 Referring to Figure 3 there is shown a block diagram of a more detailed example of the device. In particular, the processing unit 10 is in electrical communication with one or more 5 electronic components of the engine. The processing unit 10 can be in electrical communication with a throttle position sensor 320, wherein the processing unit 10 monitors a throttle signal indicative of at least one of actuation of a throttle of the engine and a position of the throttle. The processing unit 10 can be electrical communication with a velocity sensor 370, such as a tachometer, speedometer, or the like, wherein the 10 processing unit 10 monitors a velocity signal indicative of at least one of the vehicle undergoing motion and a velocity of the vehicle. The processing unit 10 can be in electrical communication with temperature sensor 340 and/or gauge 345, wherein the processing unit 10 monitors a temperature signal indicative of a temperature of the engine. The processing unit 10 can be in electrical communication with a reverse gear indicator 15 310, such as the reverse tail light of the vehicle, wherein the processing unit 10 monitors whether the vehicle is in reverse gear. The processing unit 10 can be in electrical communication with a manifold absolute pressure sensor 315, wherein the processing unit 10 monitors a manifold absolute pressure (MAP) signal indicative of a manifold absolute pressure. The processing unit 10 can be in electrical communication with a mass air flow 20 (MAF) sensor 325, wherein the processing unit 10 monitors a mass air flow (MAF) signal indicative of a mass of air flow entering the engine. The processing unit 10 can be in electrical communication with one or more auxiliary power consuming units 355, and/or the switch 350 thereof, wherein the processing unit 10 monitors an auxiliary power consumption signal indicative of one of the auxiliary power consuming units being 25 actuated. The processing unit 10 can be in electrical communication with a cruise control switch 380 of the vehicle, wherein the processing unit 10 monitors a cruise control signal indicative of an actuation of a cruise control mode for the vehicle. The processing unit 10 can be in electrical communication with an ignition switch 330, wherein the processing unit 10 can monitor an ignition signal indicative of a state of the ignition switch 330 of the 30 engine.

WO 2012/009767 PCT/AU2011/000933 -14 The processing unit 10 generally includes memory 415, 425 (see Figure 4) which stores therein data indicative of rules which the processing unit 10 applies to the monitored one or more operating signals 20 to determine if the operating condition has been satisfied. The data indicative of the rules are generally stored in non-volatile memory of the processing 5 unit 10. Still referring to Figure 3, the device 1 can include a mode input unit 390 which is in electrical communication with the processing unit 10 and is selectively operable to allow a user to select an operating mode of the device 1. The device can also be in electrical 10 communication with an instrument panel indicator 395 to provide feedback upon the mode of the device 1. In some embodiments, the mode input unit 390 and the instrument panel indicator 395 can be an integrated unit. The processing unit 10 may also be in electrical communication with the battery 360 of the 15 engine, wherein a fuse 365 is connected intermediately. Output ports of the processing unit 10 are in electrical communication with one or more switching units 305 which are in turn in electrical communication with the one or more fuel injectors 30. The device 1 is retrofittably installed by installing an electrical cable between each 20 electronic component to be monitored and input ports of the processing unit 10. An electrical cable is also installed between a trigger line 60a (i.e. an electrical line which triggers the firing of one of the fuel injectors) of the engine control unit 50 to one of the input ports of the processing unit 10. Electrical connections between the power supply 360 of the vehicle (i.e. the battery) and each fuel injector 30 are disconnected. Each fuel 25 injector 30 is then placed in electrical communication with the switching units 305 of the device I which are in turn in electrical communication with the output ports of the processing unit 10. Each switching unit 305a-305n is then placed in electrical communication with the power supply 360. Another electrical cable in installed which extends between the power supply 360 and the processing unit 10. Once the electrical 30 connections have been successfully completed, the device can be mounted to the vehicle. The mode input unit 390 of the device I can be mounted on or adjacent an instrument WO 2012/009767 PCT/AU2011/000933 -15 panel of the vehicle such that the user of the vehicle can selectively operate the device 1 during operation of the vehicle. Referring to Figure 4 there is shown a schematic of an example of the processing unit 10. 5 In particular, the processing unit 10 can include one or more microprocessors 410, 420 which are in electrical communication with at least some of the electrical components discussed above. In this particular configuration, there is shown two microprocessors 410, 420 which are in 10 electrical communication with each other. A first microprocessor 410 is configured to determine if the engine satisfies the operating condition. Once the first microprocessor 410 has determined that the operating condition has been satisfied, the first microprocessor 410 activates a first control signal 431 received by the second microprocessor 420 to cause the second microprocessor 420 to apply an injector restriction sequence to thereby restrict the 15 actuation of one or more of the injectors 30a-30n whilst the first operating condition has been satisfied. The first microprocessor 410 continues to monitor the one or more operating signals 20 whilst the one or more injectors 30 are being restricted from actuation. When the first microprocessor 410 determines that the operating condition is no longer being satisfied based on the one or more operating signals 20 being monitored, the first 20 control signal 431 is deactivated, thereby stopping the actuation of the one or more fuel injectors 30, thus allowing the fuel injectors 30 to actuate in an uninhibited manner. The second microprocessor 420 is in electrical communication with the one or more injectors 30a-30n. The second microprocessor 420 is also in electrical communication with 25 the engine control unit 50 to detect the trigger signal 60a of at least one of the injectors 30a. The second microprocessor 420 is configured to detect when the trigger signal 60a emitted by the engine control unit 50 to detect a fuel injector firing cycle. The trigger signal 60a is generally considered a change in voltage. In a majority of vehicles, the trigger signal 60a is the change of the voltage from high to ground. However, it will be 30 appreciated that the trigger signal is a detected change on the trigger line 60a between the engine control unit and the relative fuel injector.

WO 2012/009767 PCT/AU2011/000933 -16 Upon detecting the trigger signal 60a, the second microprocessor 420 then determines one or more of the fuel injectors 30a-30n to restrict actuation thereof. Generally, the second microprocessor 420 retrieves data indicative of the injector firing sequence to determine 5 which injector to restrict. Upon subsequent fuel injector firing cycles, the second microprocessor 420 cyclically progresses to the next injector 30 indicated in the injector firing sequence. Upon determination of the one or more injectors 30 to restrict, the processing unit 10 10 restricts the determined one or more injectors 30a-30n from actuating, thereby reducing the amount of fuel consumed whilst the operating condition is satisfied. The first and second microprocessors 410, 420 may include memory 415, 425 which store therein executable instructions which are executed by each respective microprocessor 15 during operation. The first and second microprocessors 410, 420 may include FLASH memory which stores therein the executable instructions, however other types of non volatile memory can be used. In particular, memory 415 associated with the first microprocessor 410 may store therein 20 data indicative of one or more operating thresholds and/or parameters and one or more rules for comparing the monitored one or more operating signals 20 to the one or more operating thresholds to determine if the operating condition has been satisfied. The memory 425 associated with the second microprocessor 420 may store therein one or 25 more injector restriction sequences. In one form, the memory 425 of the second microprocessor 420 stores therein a plurality of injector restriction sequences indicative of the fuel injector firing orders for various models of vehicles. As would be appreciated by those skilled in the art, a plurality of fuel injector firing orders exist for various types of multi-cylinder internal combustion engines. The device 1 includes a sequence input unit 30 335, which is generally in electrical communication with the second microprocessor 420, to allow the user, or preferably the auto-electrician who installs the device 1, to select one WO 2012/009767 PCT/AU2011/000933 -17 of the injector sequences to be applied when the operating condition has been satisfied. The second microprocessor 420 can retrieve the selected injector restriction sequence from memory 425 in accordance with the sequence input unit 335. The sequence selection unit 335 can be provided in the form of one or more switches. Each injector restriction 5 sequence can be provided as an executable binary which is stored in the memory 425 and retrieved by the second microprocessor, according to the sequence input device, when the device 1 is turned on and executed accordingly. The executable instructions, when executed, cause the processing unit 10 to cyclically 10 restrict a portion of the fuel injectors 30a-30n from firing in the engine when the operating condition has been satisfied. For example, on a first fuel injector firing cycle, the first fuel injector is restricted, then on the second fuel injector firing cycle the first fuel injector is allowed to first but the fifth fuel injector is restricted. In particular, the processing unit 10 cyclically selects the one or more fuel injectors 30a-30n to restrict by sequentially 15 progressing through the plurality of injectors 30a-30n indicated in the injector firing sequence retrieved from memory 425. In this arrangement, the processing unit 10 can be configured to detect a trigger signal 60a from the engine control unit 50, and then restrict a first portion of the injectors 30a-30n from firing during the first injector firing cycle in the event that the operating condition has been satisfied. The processing unit 10 can then 20 detect a subsequent trigger signal 60a from by the engine control unit 50, wherein the processing unit 10 restricts a different portion of injectors 30a-30n from firing during a following injector firing cycle whilst the operating condition is satisfied. The processing unit 10 may be configured to restrict the portion of injectors 30a-30n by 25 creating an open circuit between a power supply (i.e. the battery of the vehicle) and one of the terminals of the injector to be restricted, as shown in Figure 3 by the switching unit 305. The switching unit can include a plurality of switches which are actuable by the processing unit 10. 30 More specifically, referring to Figure 5, there is shown a schematic of a single injector in electrical communication with a switch 305a of the device 1. The following schematic is WO 2012/009767 PCT/AU2011/000933 -18 discussed in relation to a negative trigger fuel injector which is generally used in a majority of vehicles. However, it will be appreciated that the switching unit 305 can be reconfigured to operate for a positive trigger fuel injector by altering the logical outputs by portions of the switching unit 305. 5 The switch 305a generally is provided in the form of a transistor which can be actuated to a saturated mode or cut-off mode by a signal output by the processing unit 10 at a respective output port. In particular, when the operating condition has not been satisfied, the processing unit 10 outputs a logical high voltage to the base of the transistor 305a. This 10 results in the transistor being placed into the saturated mode, which results in the positive terminal of the injector having a positive voltage, generally in the range of approximately 12 to 14 volts. When the trigger signal 60a from the engine control unit is emitted (i.e. generally by setting the negative terminal of the fuel injector to ground), the respective fuel injector 30a fires. However, when the processing unit 10 determines that the operating 15 condition has been satisfied, the respective output port of the processing unit 10 is set to logical low, thereby providing a low voltage at the base of the transistor 305a, resulting in the transistor 305a being actuated into the cut-off mode, resulting in no current being able to flow from the collector of the transistor 305a to positive terminal of the respective fuel injector 30a. As a result, the fuel injector 30a cannot fire when the trigger signal 60a is 20 received from the engine control unit 50, thereby restricting the actuation of the respective fuel injector. As shown in Figure 3, the switching unit 305 can also be in electrical communication with a selectively operable current source 510, as shown also shown in more detail in Figure 5. 25 Generally, each fuel injector 30 is in electrical communication with a current source 510, wherein the current source 510 is in electrical communication with the engine control unit 50 via the respective trigger line 60. The current source includes an inverter circuit configuration 520 and a dummy resistor load R3 to simulate the firing of the fuel injector 30 and a transistor TI. When the processing unit 10 determines that the operating condition 30 has been satisfied, resulting in the transistor 305a being actuated to the cut-off mode, the collector of the transistor 305a pulls an input of the ground via resistor RI, thus resulting in WO 2012/009767 PCT/AU2011/000933 -19 a high output being output to the transistor TI, resulting in a current being fed back to the engine control unit 50 on the respective trigger line 60. The selectively operable current source 510 is advantageous for vehicles where the engine control unit 50 monitors the firing of each fuel injector 30, wherein in the event that one of the fuel injectors 30 is not 5 sensed as being fired, a check light is displayed on the instrument panel. By feeding back a simulated firing signal to the engine control unit 50 when the respective fuel injector 30 is restricted from actuation, the check light of the vehicle is not displayed to the user of the vehicle. 10 As discussed in relation to Figure 3, the device I can include the mode input unit 390 which is in electrical communication with the processing unit 10. Actuation of the mode input unit 390 allows the user to select the mode of operation of the device 1. Generally, the mode input unit is generally provided as a button which is mounted within the vehicle, such as on the instrument panel of the vehicle. The button can include the instrument panel 15 indicator 395 in the form of a light emitting portion indicative of the mode of the device 1. Preferably, in the event that a light is emitted from the light emitting portion of the button, the device I is in an active mode, and when no light is emitted from the light emitting portion of the button, the device I is in an inactive mode. In the active mode, the processing unit 10 restricts actuation of the one or more injectors 30 in the event that the 20 operating condition has been satisfied. In the inactive mode, the injectors are able to freely operate uninhibitedly without restriction from the device 1, despite the operating signals indicating that the operating condition has been satisfied. The mode input unit can also be selectively operated by the user to place the device I in an 25 initialisation mode. In particular, upon selection of the initialisation mode via actuation of the mode input device 390, the processing unit 10 monitors, and stores in memory 415 of the processing unit 10, one or more operating parameters of the engine at a low load operating state for use in determining if the operating condition has been satisfied. The low load operating state can include the engine being in an idle state, or travelling at a low 30 velocity, after the engine has been running for at least period of time suitable for the engine to warm, for example one minute, such that the operating signals of the engine are WO 2012/009767 PCT/AU2011/000933 -20 indicative of a low load state. The user can then selectively operate the mode input unit 390 to place the device 1 in the initialisation mode which is generally performed by pressing and holding the button for a threshold period of time, for example 10 seconds, wherein the processing unit begins to monitor and store in memory one or more parameters 5 of the engine which can be used as thresholds for rules to determine if the engine satisfies the operating condition. This initialisation mode enables the device I to be retrofitted to various types of vehicles which may have varying low load operating parameters. Referring to Figure 6, there is shown a flowchart illustrating a method 600 carried out for 10 the initialisation mode of the device 1. In particular, method 600 is described with reference to the processing unit 10 illustrated in Figure 4. In particular, at step 610, the method 600 includes the user starting the engine and letting the engine sit at idle for a period of time to let the engine warm. At step 620, the method includes the user placing the vehicle into a forward gear (i.e. the drive gear, non-reverse and non-park gear). By placing 15 the vehicle in the drive gear, the device 1 can measure the signal being sent to the reverse tail-light, thus allowing the device 1 to identify when the vehicle has been placed in reverse gear when in the active mode. At step 625, the user increases the velocity of the vehicle to a predefined speed, such as 20 20 kilometres per hour. The predefined speed defines the velocity threshold which define a first and second operating state, as will be discussed in more detail below. At step, 630, the method includes deactivating any auxiliary power consuming units such as air-conditioners and the like within the vehicle. At step 640, the user removes pressure from the throttle so the throttle is at rest whilst travelling at the predefined velocity. At step 650, the user 25 selectively actuates the mode input unit of the device 1 to place the device in the initialisation mode. Steps 610 to 650 are performed in order to place the vehicle in low load state to measure and record parameters that can be used for identifying if the operating condition has been 30 satisfied in order to restrict one or more injectors, such as at idle or at low load conditions such as when the vehicle is travelling but the throttle has no pressure being applied by the WO 2012/009767 PCT/AU2011/000933 -21 driver. Additionally, the velocity of the vehicle is increased to a predetermined speed such that the signal received from the velocity sensors can be calibrated as various vehicles have differing velocity sensors which emit a velocity signal in various manners. 5 The mode input unit 390 provided in the form of a button mounted in the vehicle is pressed for a predefined period of time, such as 10 seconds, in order to place the device 1 in the initialisation mode. At step 660, the method includes the processing unit 10 recording the one or more operating parameters from the one or more electrical components of the engine. The one or more operating parameters are stored in non-volatile memory 415 of 10 the processing unit 10, specifically the memory 415 associated with the first microprocessor 410 for use in determining if an operating condition has been satisfied. It is possible that the operating parameters that are recorded are threshold values that are used to determine if the vehicle satisfies the operating condition. However, it is possible that one or more operating parameters may be adjusted (e.g. adjusted by an adjustment factor 15 stored in memory, such as a constant, etc) in order to set the one or more thresholds that are stored in memory and used to determine if the vehicle satisfies the operating condition. At step 670, the device I is placed in the active mode once the operating parameters have been stored in the memory 415 of the processing unit 10. 20 Referring to Figures 7A and 7B, there is shown a flowchart illustrating a control process performed by the device 1. Specifically, the method 700 is described in relation to the processing unit 10 illustrated in Figure 4 which includes the dual processor design. In particular, once the device 1 has been placed in the active mode via actuation of the 25 input unit, the method 700 begins at step 705 where the first microprocessor 410 sets the first and second control signals 431, 432 such that no fuel injectors 30 are restricted from actuating by the second microprocessor 420. At step 710, the method 700 includes the first microprocessor 410 determining if the 30 engine is warm. In particular, the method 700 includes the first microprocessor 410 comparing the temperature, indicated by the temperature signal, against the temperature WO 2012/009767 PCT/AU2011/000933 - 22 threshold parameter stored in step 660 during the initialisation mode. In the event that the first microprocessor 410 determines, based on the comparison, that the engine is warm, the method proceeds to step 715, otherwise the method proceeds back to step 705 in a continuous loop. 5 At step 715, the method 700 includes the first microprocessor 410 determining if the ignition is actuated. In particular, the first microprocessor 410 compares the ignition signal against the parameter captured during initialisation to determine if the ignition is actuated. In the event of a successful comparison, the method proceeds to step 720, otherwise the 10 method proceeds back to step 705 in a continuous loop. At step 725, the method 700 includes first microprocessor 410 determining if the current mode of the device I is the active mode. If the first microprocessor 410 determines that the device is in the active mode, the method proceeds to step 730. Otherwise, in the event that 15 the device is in the initialisation mode, the method proceeds to method 600. Alternatively, in the event that the first microprocessor 410 determines that the device has been placed in the inactive mode the method waits until the device is placed in the active mode and then returns to step 705. 20 At step 730, the method 700 includes the first microprocessor 410 comparing the throttle position to a threshold throttle position. In the event that the throttle position fails to satisfy a throttle position threshold, the method 700 proceeds to step 735. In the event that the throttle position satisfies a throttle position threshold indicating that the user of the vehicle has actuated the throttle of the engine to a position which is indicative of the engine being 25 under load, the method 700 proceeds to step 731 where the first microprocessor 410 sets the first and second control signals 431, 432 (for example, set logical low) such that second microprocessor 432 fails to interfere with the operation of fuel injectors. The method proceeds back to step 715. 30 At step 735, the method includes the first microprocessor 410 determining if the vehicle has been placed in reverse gear. In particular, during method 600, the first microprocessor WO 2012/009767 PCT/AU2011/000933 - 23 410 sensed the signal travelling to the reverse tail-light when the vehicle is placed in a non reverse (i.e. drive) gear. This signal may be high or low value depending upon the model of vehicle. The first microprocessor 410 compares the currently sensed reverse gear signal against the stored parameter to determine if the vehicle is in reverse gear. In the event that 5 the first microprocessor 410 determines that the vehicle is in the reverse gear, the method 700 proceeds to step 731 previously discussed. Otherwise, if the vehicle is in a non-reverse gear, the method proceeds to step 740. This feature of only restricting one or more of the injectors 30 from actuation when the 10 vehicle is placed in a non-reverse gear is beneficial when a user is performing a reverse park. In some vehicles, the vehicle may be difficult to drive in reverse gear when one of the injectors is restricted from actuation during each firing cycle. Thus, the first microprocessor 410 is configured to sense if the vehicle is in a reverse gear and if so to set the first and second control signals 431, 432 (for example, set to logical low) such that the 15 second microprocessor does not interfere with the operation of the fuel injectors. At step 740, the method 700 includes the first microprocessor determining, based upon the velocity signal, if the vehicle satisfies a velocity threshold. The velocity threshold can be a value that is stored in the memory associated with the first microprocessor which is not 20 generally set during initialisation performed in method 600. Generally, the velocity threshold may be predefined value, such as 20km/hr, by the manufacturer of the device 1. The velocity threshold defines two operating states. In particular, the vehicle can be considered operating in a first operating state if the first microprocessor 410 determines that the vehicle is travelling at a velocity that does not equal and/or exceed the velocity 25 threshold (i.e. low speed). The vehicle can alternatively be considered to be operating in a second operating state if the first microprocessor determines that the vehicle is travelling at a velocity that equals and/or exceeds the velocity threshold (i.e. high speed). In the event that the vehicle is in a first operating state, the method proceeds to step 745. Otherwise, the vehicle is travelling in a second operating state wherein the method proceeds to step 741. 30 WO 2012/009767 PCT/AU2011/000933 -24 At step 741, the method includes the first microprocessor setting the second control signal 432 (for example, set to logical high) to indicate to the second microprocessor 420 that multiple fuel injectors 30 are to be restricted during each fuel injector firing cycle. In particular, the second microprocessor 420 is in electrical communication with the trigger 5 line 60a from the engine control unit 50, wherein upon detection of a trigger signal 60a, multiple fuel injectors are restricted for each fuel injector firing cycle in accordance with the injector restriction sequence data stored in memory 425 of the second microprocessor 420. The second microprocessor 420 continues to restrict multiple fuel injectors 60 per firing cycle until 'a change in the second control signal 432 (for example, a change from 10 logical high to low) is received from the first microprocessor 410 as a result of the operating condition no longer being met or that the engine is in the first operating state. Once the second control signal 432 is set (for example, logical high) by the first microprocessor 410 to restrict multiple fuel injectors 30 per fuel injector firing cycle, the method 700 then proceeds back to step 715. 15 At step 745, the method 700 includes the processing unit 10 determining, based on the auxiliary power consumption signal, if one or more auxiliary power consumption units are currently actuated (i.e. the air conditioner being on). If one or more of the auxiliary power consumption units are currently actuated, the method 700 proceeds to step 731 so no 20 injectors are restricted for the fuel injector firing cycle. In the event that no auxiliary power consumption units are currently actuated, the method 700 proceeds to step 750. It will be appreciated from method 700 that in the event that the vehicle is travelling at a velocity which exceeds the velocity threshold, multiple fuel injectors 30 are restricted from 25 actuation in step 741 despite the one or more of the auxiliary power consumption units currently under actuation. This configuration has been implemented due to the momentum of the vehicle at a speed satisfying the velocity threshold is sufficient to continue to turn the crankshaft of the vehicle despite the reduction in torque as a consequence of the actuated auxiliary power consuming unit. 30 WO 2012/009767 PCT/AU2011/000933 -25 At step 750, the method 700 includes the first microprocessor 410 setting the first control signal 431 (for example, set to logical high) such that the second microprocessor 420 restricts the actuation of a single fuel injector 30 per fuel injector firing cycle, in accordance with the injector restriction sequence stored in memory 425 of the second 5 microprocessor 420. It will be appreciated that whilst only a number of operating signals 20 have been utilised in method 700 to determine if the operating condition has been satisfied, a number of other operating signals can be used and compared against thresholds by the processing unit 10 as 10 mentioned above to determine if an operating condition has been satisfied. Referring to Figure 8 there is shown a method 800 performed by the second microprocessor for altering the actuation of a single injector per fuel injector firing cycle. It will be appreciated that the reference to a "first injector" and the like in the following 15 flowchart refers to the first injector in the fuel injection firing order specified by the fuel injection restriction sequence selected via the sequence input unit, rather than injector number 1. It will also be appreciated that the following method 800 is described in relation to a four-cylinder vehicle, however the method can be easily extended to other vehicles having more or less cylinders. 20 In particular, at step 805, the method 800 includes the second microprocessor 420 determining if an input port for receiving the first control signal 431 from the first microprocessor 410 is indicative of a request to begin the single fuel injector restriction process (e.g. has the first control signal been set logical high?). In the event of an 25 unsuccessful determination, the method 800 continues to perform step 805 in a continuous loop until the determination of step 805 is successful. In the event of a successful determination, the method 800 proceeds to step 810. At step 810, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 800 proceeds to step 815 where the second microprocessor 420 30 restricts the first fuel injector 30a in the fuel injector firing order. It will be appreciated that WO 2012/009767 PCT/AU2011/000933 - 26 the second to fourth fuel injectors are allowed to fire in an unrestricted manner in the fuel injection firing cycle. At step 820, the method 800 includes the second microprocessor 420 determining if the 5 first control signal 431 is still set (e.g. logical high) indicating that the fuel restriction process is to continue. In the event of an unsuccessful determination, the method 800 continues to perform step 820 until a successful determination occurs. Upon a successful determination, the method 800 proceeds to step 825. At step 825, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 10 60a is received, the method 800 proceeds to step 830 where the second microprocessor 420 restricts the second fuel injector 30b in the fuel injector firing order. It will be appreciated that the switching unit associated with the first fuel injector has been closed since step 815 (this can be in response to detecting the trigger signal 60a) to ensure that the first fuel injector fires. Thus, the first, third and fourth fuel injectors are allowed to fire in an 15 unrestricted manner in the fuel injection firing cycle. At step 835, the method 800 includes the second microprocessor 420 determining if the first control signal 431 is still set (e.g. logical high) indicating that the fuel restriction process is to continue. In the event of an unsuccessful determination, the method 800 20 continues to perform step 835 until a successful determination occurs. Upon a successful determination, the method 800 proceeds to step 840. At step 840, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 800 proceeds to step 845 where the second microprocessor 420 restricts the third fuel injector 30c in the fuel injector firing order. It will be appreciated 25 that the switching unit associated with the first fuel injector has been closed since step 830 (this can be in response to detecting the trigger signal 60a) to ensure that the second fuel injector fires in the respective fuel injector firing cycle. Thus, the first, second and fourth fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. 30 WO 2012/009767 PCT/AU2011/000933 - 27 At step 850, the method 800 includes the second microprocessor 420 determining if the first control signal 431 is still set (e.g. logical high) indicating that the fuel restriction process is to continue. In the event of an unsuccessful determination, the method 800 continues to perform step 850 until a successful determination occurs. Upon a successful 5 determination, the method 800 proceeds to step 855. At step 855, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 800 proceeds to step 860 where the second microprocessor 420 restricts the fourth fuel injector 30d in the fuel injector firing order. It will be appreciated that the switching unit associated with the third fuel injector has been closed since step 845 10 (this can be in response to detecting the trigger signal 60a) to ensure that the third fuel injector fires. It will be appreciated that the first to third fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. The method 800 then proceeds back to step 805 to restart the restriction process at the first 15 fuel injector 30a in the fuel injector firing cycle. It will be appreciated that the switching unit associated with the fourth fuel injector closes when the method begins to perform step 815 (this can be in response to detecting the trigger signal 60a) to ensure that the fourth fuel injector fires in the next fuel injector firing cycle. 20 It will be appreciated from Figure 8 that the method 800 can be optimised to use interrupt ports for both the first control signal 431 and the trigger signal 60a. Referring to Figure 9 there is shown a method 900 performed by the second microprocessor 420 for altering the actuation of multiple injectors per fuel injector firing 25 cycle. It will be appreciated that the reference to a "first injector" and the like in the following flowchart refers to the first injector in the fuel injection firing order specified by the fuel injection restriction sequence selected via the sequence input unit, rather than injector number 1. It will also be appreciated that the following method 900 is described in relation to an eight-cylinder vehicle, however the method 900 can be easily extended to 30 other vehicles having more or less cylinders.

WO 2012/009767 PCT/AU2011/000933 -28 In particular, at step 905, the method 900 includes the second microprocessor 420 determining if an input port for receiving the second control signal from the first microprocessor is indicative of a request to begin the multiple fuel injector restriction process (e.g. has the second control signal been set to logical high?). In the event of an 5 unsuccessful determination, the method continues to perform step 905 in a continuous loop until the determination of step 905 is successful. In the event of a successful determination, the method 900 proceeds to step 910. At step 910, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 900 proceeds to step 915 where the second microprocessor 420 restricts the first and 10 second fuel injector 30a, 30b in the fuel injector firing order. It will be appreciated that the third to eighth fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. At step 920, the method 900 includes the second microprocessor 420 determining if the 15 second control signal 432 is still set (e.g. logical high) indicating that the fuel restriction process is to continue. In the event of an unsuccessful determination, the method 900 continues to perform step 920 until a successful determination occurs. Upon a successful determination, the method 900 proceeds to step 925. At step 925, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 20 60a is received, the method 900 proceeds to step 930 where the second microprocessor 420 restricts the third and fourth fuel injectors 30c, 30d in the fuel injector firing order. It will be appreciated that the switching units associated with the first and second fuel injectors have been closed since step 915 (this can be in response to detecting the trigger signal 60a in step 925) to ensure that the first and second fuel injectors fire. It will be appreciated that 25 the first, second and fifth to eighth fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. At step 935, the method 900 includes the second microprocessor 420 determining if the second control signal 432 is still set (e.g. logical high) indicating that the fuel restriction 30 process is to continue. In the event of an unsuccessful determination, the method 900 continues to perform step 935 until a successful determination occurs. Upon a successful WO 2012/009767 PCT/AU2011/000933 -29 determination, the method 900 proceeds to step 940. At step 940, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 900 proceeds to step 945 where the second microprocessor 420 restricts the fifth and sixth fuel injectors 30e, 30f in the fuel injector firing order. It will be 5 appreciated that the switching unit associated with the third and fourth fuel injector have been closed since step 930 (this can be in response to detecting the trigger signal 60a at step 940) to ensure that the third and fourth fuel injectors fire. It will be appreciated that the first to fourth, seventh and eighth fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. 10 At step 950, the method 900 includes the second microprocessor 420 determining if the second control signal 432 is still set (e.g. logical high) indicating that the fuel restriction process is to continue. In the event of an unsuccessful determination, the method 900 continues to perform step 950 until a successful determination occurs. Upon a successful 15 determination, the method 900 proceeds to step 955. At step 955, the second microprocessor 420 waits until the trigger signal 60a is received. Once the trigger signal 60a is received, the method 900 proceeds to step 960 where the second microprocessor 420 restricts the seventh and eighth fuel injectors 30g, 30h in the fuel injector firing order. It will be appreciated that the switching unit associated with the fifth and sixth fuel injectors 20 have been closed since step 945 (this can be in response to detecting the trigger signal 60a at 955) to ensure that the fifth and sixth fuel injectors fire. It will be appreciated that the first to sixth fuel injectors are allowed to fire in an unrestricted manner in the respective fuel injection firing cycle. 25 The method then proceeds back to step 905 to restart the restriction process at the first fuel injector. It will be appreciated that the switching unit associated with the seventh and eighth fuel injector have been closed since step 960 (this can be in response to detecting the trigger signal 60a at step 910) to ensure that the seventh and eighth fuel injectors fire in the next fuel injector firing cycle. 30 WO 2012/009767 PCT/AU2011/000933 -30 Again, similarly to Figure 8, it will be appreciated from Figure 9, the method 900 can be optimised to use interrupt ports for both the second control signal 432 and the trigger signal 60a. 5 It will be appreciated that operating condition is generally indicative of the engine being under low load which corresponds to a low mechanical force being applied by the engine. For example, in the instance that the vehicle is travelling 100km/hour and the user removes their foot from the throttle pedal, the engine is considered to be under low load as no mechanical force is being applied to the engine. On the other hand, when a user applies a 10 pressure to the throttle pedal, thereby accelerating the engine or at least maintaining the engine at it's current speed, a mechanical force is being applied to the engine, thus the engine is considered to be under load greater than low load, thus the operating condition has not been satisfied. 15 It will be appreciated that whilst a dual processor arrangement has been disclosed in Figure 4 and in more detail in Figures 6 to 9, it is possible that a single processor arrangement could be used. It will be appreciated that an integrated chip may also be used to perform the task of the dual processor arrangement disclosed above. 20 It will be appreciated that whilst the above arrangement provides a fuel efficiency advantage, other advantages can also be achieved. For example, as ambient air is pumped via the cylinder(s) associated with the non-actuated injector(s), a cooling effect is applied to the engine, thereby reducing the cooling requirements for the engine. Additionally, as a reduced mechanical output is being achieved by the cylinder(s) associated with the non 25 actuated injector(s), a breaking efficiency is achievable. Many modifications will be apparent to those skilled in the art without departing from the scope of the present invention.

Claims (20)

1. A device for altering fuel usage in a multi-cylinder combustion engine of a vehicle, wherein the device includes a processing unit which is retrofittably adapted to be in electrical communication with: one or more electronic components of the engine; fuel injectors of the engine; and an engine control unit of the engine; wherein the processing unit is configured to: monitor, during operation of the vehicle, one or more operating signals from the one or more electronic components; determine, based upon the one or more operating signals, if an operating condition has been satisfied; and whilst the operating condition has been satisfied: detect, from the engine control unit, a trigger signal for actuating one of the fuel injectors; and in response to detecting the trigger signal, restrict one or more of the fuel injectors from actuation in a fuel injector firing cycle; wherein the device includes a mode input unit for selectively operating the device in an initialisation mode, wherein upon selection of the initialisation mode, the processing unit monitors, and stores in memory of the processing unit, one or more operating parameters of the vehicle at a low load operating state for use in determining if the operating condition has been satisfied.

2. The device according to claim 1, wherein the processing unit is configured to cyclically progress through the plurality of injectors for restriction over multiple fuel injector firing cycles.

3. The device according to claim 1 or 2, wherein the processing unit restricts the one or more injectors from actuation by creating an open circuit between a power source and the respective one or more injectors. - 32

4. The device according to claim 3, wherein the device includes a plurality of switching units, each switching unit being in electrical communication with the power source, a respective fuel injector and the processing unit, wherein the processing unit electrically actuates one of the switching units to restrict the actuation of the respective fuel injector.

5. The device according to any one of claims 1 to 4, wherein the device includes a selectively operable current source in electrical communication with the processing unit and the engine control unit, wherein when one of the fuel injectors is restricted, the current source provides an electrical signal to the engine control unit, thereby simulating that the respective fuel injector has actuated.

6. The device according to claim 5, wherein the device includes a plurality of current sources corresponding to the plurality of fuel injectors, wherein each current source is configured to simulate actuation of a respective fuel injector.

7. The device according to any one of claims 1 to 6, wherein the mode input unit is operable for selecting: an active mode, wherein the processing unit detects if the operating condition has been satisfied and in response restricts one or more of the fuel injectors; or an inactive mode, wherein the fuel injectors operate uninhibitedly.

8. The device according to any one of claims 1 to 7, wherein the processing unit has stored in the memory sequence data indicative of an injector restriction sequence defining an order which the fuel injectors are to be restricted when the operating condition has been satisfied, wherein the processing unit retrieves and applies the sequence data when the operating condition is satisfied.

9. The device according to claim 8, wherein the memory stores therein a plurality of injector restriction sequences, wherein the device includes a sequence input unit to select one of the injector sequences to be applied when the operating condition has been satisfied. - 33

10. The device according to any one of claims 1 to 9, wherein the one or more operating signals includes at least one of: a throttle signal indicative of at least one of: actuation of a throttle of the engine; and a position of the throttle; a velocity signal indicative of at least one of: the vehicle undergoing motion; and a velocity of the vehicle; a temperature signal indicative of a temperature of the engine; a reverse gear signal indicative of the vehicle being in reverse gear; a manifold absolute pressure (MAP) signal indicative of a manifold absolute pressure; a mass air flow (MAF) signal indicative of a mass of air flow entering the engine; an auxiliary power consumption signal indicative of an auxiliary power consuming unit being actuated; a cruise control signal indicative of an actuation of a cruise control mode for the vehicle; and an ignition signal indicative of a state of an ignition unit of the engine.

11. The device according to claim 10, whilst the operating condition has been satisfied, the processing unit is configured to determine, based on the velocity signal, an operating state of the engine, wherein: whilst the velocity signal is indicative of the vehicle failing to satisfy a velocity threshold, the processing unit restricts a single fuel injector in one or more fuel injector firing cycles; and whilst the velocity signal is indicative of the vehicle satisfying the velocity threshold, the processing unit restricts multiple fuel injectors from actuating in one or more fuel injector firing cycles.

12. The device according to claim 10 or 11, wherein the processing unit is configured to determine, based on the temperature signal, if the temperature of the engine satisfies a temperature threshold, wherein in the event that the processing unit determines that the - 34 temperature threshold is unsatisfied, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly.

13. The device according to any one of claims 10 to 12, wherein the processing unit is configured to determine if the reverse gear signal indicates that the vehicle is in reverse gear, wherein in the event that the processing unit determines that the vehicle is in reverse gear, the operating condition is unsatisfied, thereby allowing the injectors to operate uninhibitedly.

14. The device according to any one of claims 10 to 13, wherein the processing unit is configured to determine, based on the auxiliary power consumption and velocity signals, if the auxiliary power consumption unit has been actuated whilst the vehicle has a velocity satisfying a velocity threshold, wherein whilst the auxiliary power consumption unit is actuating whilst the velocity threshold has been satisfied, the operating condition is satisfied, otherwise the operating condition has not been satisfied thereby allowing the injectors to operate uninhibitedly.

15. A method for altering fuel usage in a multi-cylinder combustion engine of a vehicle, wherein the method includes use of a device having a processing unit which is retrofittably adapted to be in electrical communication with: one or more electronic components of the engine; fuel injectors of the engine; and an engine control unit of the engine; wherein the method includes, in the processing unit: monitoring, during operation of the vehicle, one or more operating signals of the one or more electronic components; determining, based upon the one or more operating signals, if an operating condition has been satisfied; and whilst the operating condition has been satisfied: detecting, from the engine control unit, a trigger signal for actuating one of the fuel injectors; and in response to detecting the trigger signal, restricting one or more of the fuel injectors from actuation in a fuel injector firing cycle; - 35 wherein the device includes a mode input unit for selectively operating the device in an initialisation mode, wherein the method includes receiving input indicative of selection of the initialisation mode, wherein upon selection of the initialisation mode, the method includes the processing unit monitoring, and storing in memory of the processing unit, one or more operating parameters of the vehicle at a low load operating state for use in determining if the operating condition has been satisfied.

16. The method according to claim 15, wherein the method includes the processing unit cyclically progressing through the plurality of injectors for restriction over multiple fuel injector firing cycles.

17. The method according to claim 15 or 16, wherein the method includes the processing unit restricting the one or more injectors from actuation by creating an open circuit between a power source and the respective one or more injectors.

18. The method according to any one of claims 15 to 17, wherein the method includes receiving input indicative of a selection of: an active mode, wherein the processing unit detects if the operating condition has been satisfied and in response restricts one or more of the fuel injectors; or an inactive mode, wherein the fuel injectors operate uninhibitedly.

19. The method according to any one of claims 15 to 18, wherein the processing unit has stored in the memory sequence data indicative of an injector restriction sequence defining an order which the fuel injectors are to be restricted when the operating condition has been satisfied, wherein the method includes the processing unit retrieving and restricting one or more of the fuel injectors, in accordance with the sequence data, when the operating condition is satisfied.

20. The method according to any one of claims 15 to 19, wherein the method includes monitoring the one or more operating signals including at least one of: a throttle signal indicative of at least one of: actuation of a throttle of the engine; and - 36 a position of the throttle; a velocity signal indicative of at least one of: the vehicle undergoing motion; and a velocity of the vehicle; a temperature signal indicative of a temperature of the engine; a reverse gear signal indicative of the vehicle being in reverse gear; a manifold absolute pressure (MAP) signal indicative of a manifold absolute pressure; a mass air flow (MAF) signal indicative of a mass of air flow entering the engine; an auxiliary power consumption signal indicative of an auxiliary power consuming unit being actuated; a cruise control signal indicative of an actuation of a cruise control mode for the vehicle; and an ignition signal indicative of a state of an ignition unit of the engine.