Systems, methods, and apparatus for high pressure fuel pump diagnostics

Abstract

A system includes: an engine including a plurality of combustion chambers; a fuel supply system including a fuel rail in fluid communication with a plurality of fuel injectors, each of the plurality of fuel injectors configured to provide fuel to a respective combustion chamber of the plurality of combustion chambers, and a high pressure fuel pump in fluid communication with the fuel rail; and an electronic control system in operative communication with the fuel supply system. The electronic control system is configured to diagnose a condition of the high pressure fuel pump in response to a pressure sensor output of pressure in the fuel rail.

Description

Technical Field

[0001] The present disclosure relates to internal combustion engines, and more particularly to diagnostics of high pressure fuel pumps for internal combustion engines. Background Art

[0002] Internal combustion engines utilize a fuel system with numerous components. For example, fuel system components may include injectors, fuel rails, valves, meters, filters, high-pressure fuel pumps, low-pressure fuel pumps, and associated piping and connections. To operate an internal combustion engine, it is crucial to be able to precisely time these components to deliver the required amount of fuel. Failure, leakage, degradation, and other issues with fuel system components can lead to poor or suboptimal engine performance, increased maintenance requirements, and even vehicle grounding.

[0003] Diagnostics of fuel systems of internal combustion engines, including high pressure fuel pumps, suffer from numerous shortcomings, including those related to accuracy, complexity, computational burden, precision, reliability, and robustness, among others. There remains a significant need for the unique apparatus, processes, systems, and techniques disclosed herein.

[0004] Exemplary embodiment disclosure

[0005] In order to clearly, concisely and accurately describe the exemplary embodiments of the present disclosure, the manner and process of making and using the present disclosure, and to enable the practice, making and using of the present disclosure, reference will now be made to certain exemplary embodiments, including those shown in the drawings, and specific language will be used to describe the present disclosure. However, it should be understood that no limitation of the scope of the present invention is thereby created, and the present invention includes and protects such changes, modifications and further applications of the exemplary embodiments as will occur to those skilled in the art. Summary of the Invention

[0006] One embodiment is a unique system for testing or diagnosing a high-pressure fuel pump of an internal combustion engine using a pressure sensor output from a pressure sensor connected to a fuel rail. Another embodiment is a unique method for testing or diagnosing a high-pressure fuel pump. Another embodiment is a unique apparatus for testing or diagnosing a high-pressure fuel pump. Additional embodiments, aspects, objects, features, advantages, aspects, and benefits will become apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram illustrating certain aspects of an exemplary system and apparatus for high pressure fuel pump diagnostics.

[0008] Figure 2 is a schematic diagram illustrating certain aspects of an example method for high pressure fuel pump diagnostics.

[0009] Figure 3 are graphs illustrating certain aspects of example operations of example methods and systems. DETAILED DESCRIPTION

[0010] Figure 1 An embodiment of a system 100 is shown that includes a diagnostic tool 140 and an engine system 110. The diagnostic tool 140 can be selectively operatively coupled to and in operative communication with an electronic control unit (ECU) 120 of the engine system 110 via one or more communication links 130. The diagnostic tool 140 and the communication link 130 can be provided in a variety of forms and, when connected, form part of an electronic control system 122 in conjunction with the ECU 120. The diagnostic tool 140 can also be a stand-alone tool, a software tool for use on a computer, an application tool on a smart device such as a phone or tablet, or a telematics-based cloud tool.

[0011] The engine system 110 includes an engine 112 having a plurality of combustion chambers 117. A fuel supply system 114 includes a fuel rail 108 in fluid communication with a plurality of fuel injectors 118. Each of the plurality of fuel injectors 118 is configured to provide fuel to a corresponding combustion chamber of the plurality of combustion chambers 117. A high-pressure fuel pump 106 is in fluid communication with the fuel rail 108 and includes a plurality of cylinders 107 having pumping elements (E1 ... En).

[0012] The electronic control system 122 is in operative communication with the fuel delivery system 114 and is configured to: operate the high pressure fuel pump 106 , receive a pressure sensor output indicative of fuel pressure of the fuel rail 108 during diagnosis, determine a pressure rise differential between each of the plurality of cylinders 107 of the high pressure fuel pump 106 based on the pressure sensor output during diagnosis, and, in response to the pressure rise differential, display an operator-perceivable output indicative of a condition of the high pressure fuel pump 106 and / or diagnose a condition of the high pressure fuel pump 106 .

[0013] Embodiments of the fuel delivery system 114 may include a synchronized fuel pump, where the pumping ratio is constant, or a timed fuel pump, where the pumping phase is determined at the time of manufacture. In these embodiments, the pumping phase is known and can be used to diagnose the cylinder 107 without inhibiting fuel injection from the fuel injector 118.

[0014] For embodiments of the fuel delivery system 114 with non-timed but synchronized fuel pumps, where the pumping ratio is an integer but the pumping phase is unknown, injection events can be suppressed to measure and determine the fuel pump phasing. Once the fuel pump phasing is determined, fuel pressure and pumping data between the different cylinders 107 can be determined without suppressing injection. In the event of overlap between pumping and injection, it may be necessary to suppress injection.

[0015] For embodiments of the fuel delivery system 114 having an unsynchronized fuel pump, injection events are suppressed to determine phasing, and fuel pressure and pumping data are also determined between the different cylinders 107 during the measurement period. This is because injection and pumping can be mixed, thereby enabling fuel pressure measurement and determination of pumping imbalances between the cylinders 107.

[0016] In some embodiments, the diagnostic tool 140 may be implemented and executed in conjunction with one or more computing devices present at the location of the engine system 110 (e.g., at a service station or another service point where the engine system 110 is located). In such embodiments, the communication link 130 may include one or more physical connections to the engine system 110, for example, via an OBD II interface, a J1939 interface, or various other interfaces. In some embodiments, the diagnostic tool 140 may be hardwired to an external service tool, or may be a standalone device.

[0017] In some embodiments, the diagnostic tool 140 may be implemented and executed in conjunction with one or more computing devices located remotely from the engine system 110, and the communication link 130 may include one or more networks, including wired and / or wireless networks or network components, configured and operable to provide communication between the diagnostic tool 140 and the ECU 120 of the engine system 110. Some such embodiments may include one or more computing devices located remotely from the engine system 110 and communicating with the ECU 120 of the engine system 110 via a telematics system. Some such embodiments may include a combination of one or more computing devices located remotely from the engine system 110 and one or more computing devices present at the location of the engine system 110 (e.g., at a service station or another service point where the engine system 110 is located), the two computing devices communicating via remote communication, such as cloud-based telematics data.

[0018] Although the diagnostic tool 140 Figure 1 1 as being external to the engine system 110, in some embodiments, the diagnostic tool 140 may be embedded in or otherwise provided within the engine system 110. In some such embodiments, the diagnostic tool 140 may be embedded in or otherwise provided within and executed by the ECU 120 and / or other components of the electronic control system (ECS) of the engine system 110. In some such embodiments, the communication link 130 may include one or more intra-ECU or intra-ECS communication channels, or may be omitted where a communication link is not required, such as where there is an internal diagnostic tool as part of the ECU 120 and / or ECS 122.

[0019] The engine system 110 may also include a starter motor 116 operatively coupled to the engine 112 and the ECU 120, and a fuel supply system 114 operatively coupled to the engine 112 and the ECU 120. In the illustrated embodiment, the engine 112 is a direct-injection, reciprocating piston-type internal combustion engine that is configured and operable to combust fuel injected directly into corresponding combustion chambers of a plurality of combustion chambers 117 by one or more fuel injectors 118. It should be understood that the engine 112 may be configured and provided in various forms, including various numbers of combustion chambers 117 and various numbers of fuel injectors 118.

[0020] In the illustrated embodiment, the fuel supply system 114 is configured and provided as a high-pressure common rail (HPCR) fuel supply system. In other embodiments, the fuel supply system can be provided in various other forms that will occur to those skilled in the art given the benefit and insight of this disclosure. The fuel supply system 114 includes a fuel rail 108 that receives pressurized fuel from a high-pressure fuel pump 106 and provides pressurized fuel to fuel injectors 118. In the illustrated embodiment, the fuel pump 106 is provided and configured as a high-pressure fuel pump having a plurality of cylinders 107, each having corresponding pump elements (E1...En). In an embodiment, the high-pressure fuel pump 106 includes a plurality of in-cylinder piston-type pump elements (E1...En) located in corresponding cylinders of the cylinders 107, the plurality of in-cylinder piston-type pump elements being configured to pressurize the fuel received by the fuel pump 106 and provide the pressurized fuel from each of the cylinders 107 to the fuel rail 108.

[0021] In an embodiment, the high-pressure fuel pump 106 is a fuel pump that pressurizes fuel in the fuel rail 108 by reciprocating motion of pump elements (E1 ... En) via cam lobes on a pump camshaft that rotates in a timed relationship with an engine crankshaft 123. The ECU 120 is in operative communication with, for example, an engine position sensor and is configured to receive engine position measurements or signals that are used to correlate the crank angle position of the crankshaft 123 with the positions of the pump elements (E1 ... En) in order to determine the pumping phase of the pump elements (E1 ... En).

[0022] Other embodiments contemplate other techniques for determining the pumping phase of the pumping elements (E1 ... En) with the crankshaft 123, such as a lookup table. As a result, as discussed further below, a specific pumping element (E1 ... En) and the pressure sensor signal output it generates in the fuel rail 108 can be identified. As discussed above, for embodiments with synchronized fuel pumps, the pumping phase is predetermined. For some embodiments with unsynchronized fuel pumps, pumping phase determination may not be required.

[0023] In an embodiment, the engine 112 has a plurality of combustion chambers 117 formed by a corresponding number of cylinders of the engine 112. For example, the engine 112 may be provided with four or six cylinders, each cylinder including a combustion chamber for receiving fuel from a corresponding fuel injector 118. In an embodiment, the high pressure fuel pump 106 is provided and configured as a 3-cylinder pump, wherein each pump cylinder produces two pumping events per revolution of the pump camshaft. Other embodiments contemplate other numbers of pumping events per revolution of the pump camshaft, such as one pumping event or three or more pumping events per revolution of the pump camshaft. Other embodiments contemplate a high pressure fuel pump 106 having two cylinders, or four or more cylinders. It should be understood that this configuration is an example of an engine system suitable for operation according to the apparatus, controls, diagnostics, processes, systems and techniques of the present disclosure.

[0024] An inlet metering valve (IMV) 104 is disposed at or upstream of the inlet of the fuel pump 106 and is operatively coupled to and controllable by the ECU 120 to meter or regulate the flow of fuel entering the fuel pump 106. It should be understood that the IMV 104 may also be referred to as a volume control valve, a flow control valve, a magnetic proportional valve, or various other technical terms. Alternatively, the IMV 104 may be disposed at the inlet of each cylinder 107 of the fuel pump 106.

[0025] Each IMV 104 is configured and operable to receive fuel pumped from a fuel tank 102 by a pump 103, which may be configured and provided as a low-pressure fuel pump. An ECU 120 is in operative communication with the IMVs 104 and is configured to electronically control the IMVs between a fully closed position, which allows a minimum fuel flow (e.g., substantially no fuel flow) to the fuel pump 106, and a fully open position, which allows a maximum fuel flow to the cylinders 107 of the fuel pump 106.

[0026] ECS 120 is also in operative communication with pressure sensor 119 and is configured to receive pressure measurements from the pressure sensor, which is configured to sense fuel pressure in fuel rail 108. In an embodiment, pressure sensor 119 is a high-precision, fast-response pressure sensor that measures pressure in fuel rail 108 at a response rate of 2 milliseconds or less. In an embodiment, pressure sensor 119 is capable of generating a high-frequency output for pressure measurements in fuel rail 108. In an embodiment, the high-frequency signal from the pressure sensor output is 10 kilohertz. Other embodiments contemplate other high frequencies based on processor capabilities and algorithm requirements.

[0027] The ECU 120 is also in operative communication with the fuel injector 118 and is configured to control the operation of the fuel injector to inject fuel into the combustion chamber 117 of the engine 112. The ECU 120 is also in operative communication with the fuel injector 118 and is configured to control the fuel injector between a fully closed position, which does not permit fuel injection into the combustion chamber 117, and an open position, which permits fuel injection. The ECU 120 is also in operative communication with the crank engine 112 and is configured to provide a control signal to the crank engine for selectively operating the starter motor 116. Additionally or alternatively, the control signal for operating the starter motor 116 may be provided to the crank engine 112 in response to a technician command or triggering engagement or operation of the starter motor 116. In some embodiments, an automatic starter may be present and may also be controllable via a body control module and may include a button for manual starting.

[0028] ECU 120 is an example of a component of ECS 122 that is configured and operable to execute operating logic that defines various control, diagnostic, management, and / or regulatory functions. For example, a non-transitory memory medium may be configured with instructions that are executable by a processor to perform a plurality of actions, evaluations, or operations, including those described herein. The operating logic of ECU 120 or other ECS 122 components may be in the form of dedicated hardware, such as a hardwired state machine, an analog computing machine, programmed instructions, and / or various other forms as will occur to those skilled in the art.

[0029] Although the ECU 120 is depicted as a single unit in the illustrated example, it should be understood that one or more processors, one or more non-transitory memory media, and associated components may be provided as multiple units or physical packages, or distributed across or between multiple units or physical packages. For example, one or more processors, such as programmable microprocessors or microcontrollers of the solid-state integrated circuit type, may be provided in one or more control units and may be implemented in any of a variety of ways that combine or distribute control functions across one or more control units in various ways. Other components or subsystems of the ECU 120 and / or its associated ECS 122 may also be configured or provided in this manner.

[0030] refer to Figure 2 , illustrates an exemplary method 200 that may be implemented and performed, in whole or in part, in conjunction with a system such as system 100. Method 200 is one example of a method for performing diagnostics or testing of a fuel pump, such as high-pressure fuel pump 106, according to the present disclosure.

[0031] Method 200 begins at start operation 202 and proceeds to conditional 204 which tests whether one or more test or diagnostic start conditions are satisfied. The one or more test or diagnostic start conditions may include multiple conditions that may vary depending on the particular system on which method 200 is executed.

[0032] For example, one or more test or diagnostic start conditions may include engine and / or fuel system conditions that may be established or selected to provide the operating conditions required or desired for testing a fuel pump, such as high-pressure fuel pump 106. Such conditions may include, for example: the presence or absence of, or certain fault codes for, engine 112, pressure sensor 119, or other components of fuel system 114; engine 112 operating at idle; the open or closed state of IMV 104; a pressure, such as fuel pressure of fuel rail 108, below or above a threshold; or other conditions indicative of, or suitable as a proxy for, a condition of engine 112 and / or a fuel delivery system, such as fuel delivery system 114.

[0033] In some embodiments, one or more test start conditions may include initiation of a test or diagnostic by a technician and / or a diagnostic tool such as diagnostic tool 140. Such embodiments may include, for example, embodiments in which method 200 is performed during an off-mission diagnostic, service, or repair event.

[0034] In some embodiments, one or more test or diagnostic start conditions may include a key-on condition and / or one or more engine start or engine idle conditions. Such embodiments may include, for example, embodiments in which method 200 is performed each time an engine, such as engine 112, is started during operation, or periodically or periodically when the engine is started, or in conjunction with an event such as a detection of an error, fault, or fault condition that may be associated with the high pressure fuel pump.

[0035] If conditional 204 evaluates to negative, method 200 proceeds to operation 206, where method 200 establishes and / or waits for the establishment of the start condition evaluated by conditional 204. If conditional 204 evaluates to positive, method 200 proceeds to optional operation 208, which may override one or more idle conditions of engine 112 and fuel system 114. For example, operation 208 may include increasing the speed of engine 112 to above idle speed while simultaneously reducing the pressure in fuel rail 108 to below the nominal idle pressure. In a specific example, the speed of engine 112 may be increased to 1800 revolutions per minute while simultaneously reducing the pressure in fuel rail 108 to 500 bar. Other examples contemplate that other engine speeds (such as idle speed) and fuel rail pressures may be employed.

[0036] From operation 208, method 200 may proceed to optional operation 210, which may inhibit injection from a fuel injector, such as fuel injector 118, by, for example, inhibiting an injection control signal or otherwise controlling fuel injector 118 to not inject. For example, as discussed above, inhibiting injection from a non-synchronized fuel pump may be used to directly measure continuous pumping data without determining pumping phase. For a non-timed synchronous pump, inhibiting injection may be used to determine pumping phase at optional operation 212. For a timed and synchronized fuel pump with a constant pumping ratio, the pumping phase is known and does not need to be determined, and inhibiting injection is not necessary.

[0037] Optional operation 212 determines the pumping phase of the pumping elements (E1 ... EN) of the non-timed and synchronized high-pressure fuel pump 106. Pumping phase determination at operation 212 gathers pumping data, including high-frequency signals for pressure measurements from pressure sensor 119. Operation 210 correlates each pumping element (E1 ... En) with a corresponding high-frequency pressure signal generated by each pumping element (E1 ... En), as indicated by pressure sensor measurements in the fuel rail 108 gathered from the pressure sensor output of pressure sensor 119. The pumping elements (E1 ... En) can be correlated to the crank angle position of the crankshaft 123 and the corresponding rotational position of the pump camshaft that moves the pumping elements (E1 ... En), thus identifying the pressure signal output generated by each pumping element (E1 ... En).

[0038] From operation 212 , method 200 proceeds to conditional 214 to determine whether sufficient pumping data has been collected to perform a diagnostic or test during operation 212 . If conditional 214 evaluates negatively, method 200 returns to operation 208 and resets the idle override condition for engine 112 . For example, since fuel injection has been inhibited, engine speed will decrease from the override speed and fuel rail pressure will increase from the override pressure during operation 212 . When engine speed reaches a lower limit and / or fuel rail pressure reaches an upper limit, conditional 214 may evaluate whether sufficient pumping data has been collected to perform a diagnostic or test. Therefore, if conditional 214 evaluates negatively, the data collection override condition is reestablished at operation 208 to collect more pressure sensor output data.

[0039] If the conditional 214 evaluates to yes, the pressure measurement 216 may be provided to an operation 218, which all uses the pressure measurement 216 to perform one or more diagnostics or tests. The one or more diagnostics or tests may include multiple diagnostics or tests and may be combined with operations 220 and Figure 3 Describe its examples.

[0040] From operation 218, method 200 proceeds to operation 220, which determines a pump imbalance condition of the high pressure fuel pump 106. A pump imbalance condition may include, for example, one or more pumping elements (E1 ... En) generating a high frequency pressure sensor output that differs by more than a threshold amount from the high frequency pressure sensor outputs of the other pumping elements (E1 ... En).

[0041] For example, Figure 3 Graph 300 is shown plotting hypothetical high-frequency pressure sensor data resulting from operation of a high-pressure fuel pump 106 including three pumping elements 302, 304, 306. The high-frequency output of pumping elements 302, 304 indicates a first pressure increase 308 in fuel rail 108, and the high-frequency output of pumping element 306 indicates a second pressure increase 310 in fuel rail 108 caused by pumping element 306.

[0042] For example, if the difference between the first pressure increase 308 and the second pressure increase 310 generated during operation 212 exceeds a threshold amount, a fault condition of the pumping element 306 may be determined. It should be understood that the diagnostic is not limited to evaluating a single pumping element, but rather, if the associated pressure responses of two or more pumping elements differ from an expected or baseline pressure response by more than a threshold amount, two or more pumping elements may be diagnosed as faulty. It should also be understood that Figure 3 is simplified, and in actual operation there are several additional data points between the pressure measurements shown, and the pressure measurements may be filtered and undergo other data processing.

[0043] It should be understood that all or a portion of method 200 may be executed on a cloud-based server and / or database. For certain engine operating conditions, any expected values ​​of pressure responses and / or differences between pressure responses may be dynamically adjusted based on the distribution of available data on the cloud.

[0044] Return to Figure 2 From operation 220, the method 200 continues to operation 222 to output one or more pump diagnostic or test results of the one or more diagnostics performed by operation 220. Outputting the one or more diagnostic results at operation 222 may include communicating, displaying, transmitting, storing, or otherwise outputting the one or more diagnostic results to display an operator-perceivable output indicative of a condition of the high pressure fuel pump 106 and / or diagnosing a condition of the high pressure fuel pump 106.

[0045] The diagnostic results for one or more pumping elements (E1 . . . En) may indicate that a single pumping element and / or cylinder 107 is pumping less than one or more other pumping elements and / or cylinders 107. Reduced pumping may be caused by a worn piston, a failed seal, a malfunctioning check valve, a worn cam lobe, a leak, or other conditions. Additionally, the specific one or more pumping elements and corresponding cylinders 107 may be identified for ease of repair. Method 200 may also include recording or storing test results, such as diagnostic test results, pressure sensor output data, or other operations associated therewith (e.g., test date and time and / or other diagnostic information associated with the test), removing fuel injection inhibition, and removing any other test overrides.

[0046] In an embodiment, in response to one or more pump cylinders 107 being diagnosed as unbalanced, one or more engine operating parameters are adjusted. For example, the commanded fuel amount and fuel pulses may be adjusted to compensate for the unbalanced condition. The inlet metering valve commands to one or more IMVs 104 may be adjusted to compensate for the unbalanced condition. Other operating parameter adjustments that may be made include one or more of the following: fuel injection timing, engine speed, IMV position, engine power output limits, injection duration limits, exhaust gas recirculation response, selection of engine cylinders to skip firing, and engine protection or throttle conditions.

[0047] It should be understood that Figure 3 The method described is one example of a method for identifying pressure differences corresponding to individual pumping cylinder elements. Once such information is identified, a wide range of analyses and diagnostics can be performed, including, for example, comparing or evaluating the average pressure increases of multiple pumping elements (E1...En) across multiple pumping events, and comparing or evaluating multiple pressure increases of a single pumping element for multiple pumping events. Various statistics, including variance, weighted average, and other statistical information, can also be utilized.

[0048] As described in this detailed description, the present disclosure contemplates numerous and various aspects and embodiments, including but not limited to the following. According to one aspect, a system includes an engine comprising a plurality of combustion chambers; and a fuel supply system comprising a fuel rail in fluidic communication with a plurality of fuel injectors. Each of the plurality of fuel injectors is configured to supply fuel to a corresponding combustion chamber of the plurality of combustion chambers, and a high-pressure fuel pump in fluidic communication with the fuel rail is provided. The high-pressure fuel pump includes a plurality of cylinders. The system further includes an electronic control system in operative communication with the fuel supply system. The electronic control system is configured to: operate the high-pressure fuel pump during a diagnosis of the high-pressure fuel pump; receive a pressure sensor output indicating fuel pressure of the fuel rail during the diagnosis; determine a pressure rise differential between each of the plurality of cylinders of the high-pressure fuel pump based on the pressure sensor output during the diagnosis; and, in response to the pressure rise differential, display an operator-perceivable output indicating a condition of the high-pressure fuel pump and / or diagnose the condition of the high-pressure fuel pump.

[0049] In an embodiment, the electronic control system is configured to: operate the high-pressure fuel pump without injecting fuel from the injector, and / or analyze a high-frequency signal output from the pressure sensor to determine a pumping phase of the high-pressure fuel pump and a pressure increase difference between a plurality of cylinders.

[0050] In another embodiment, the high frequency signal output from the pressure sensor is 10 kHz.

[0051] In an embodiment, the electronic control system is configured to override the engine speed limit at idle conditions while increasing fuel rail pressure during diagnostics.

[0052] In an embodiment, the electronic control system is configured to receive a pressure sensor output indicative of fuel pressure of the fuel rail and determine a pumping phase of the high pressure fuel pump over a plurality of cycles of the engine before determining the differential pressure rise.

[0053] In an embodiment, the electronic control system is operatively coupled to an external diagnostic tool.

[0054] In an embodiment, the fuel rail is a high pressure common rail fuel connected to a high pressure fuel pump.

[0055] According to another aspect of the present disclosure, a method for controlling an engine fuel supply system is provided, the engine fuel supply system including a fuel rail in fluid communication with a plurality of fuel injectors. Each of the plurality of fuel injectors is configured to supply fuel to a corresponding combustion chamber of a plurality of combustion chambers, and a high-pressure fuel pump is in fluid communication with the fuel rail. The method includes operating a high-pressure fuel pump during a diagnosis of the high-pressure fuel pump, receiving a pressure sensor output indicating a fuel pressure of the fuel rail during the diagnosis, determining a pressure rise differential between each of a plurality of cylinders of the high-pressure fuel pump based on the pressure sensor output during the diagnosis, and displaying an operator-perceivable output indicating a condition of the high-pressure fuel pump and / or diagnosing the condition of the high-pressure fuel pump in response to the pressure rise differential.

[0056] In an embodiment, the method includes operating a high-pressure fuel pump without injecting fuel from an injector, and / or analyzing a high-frequency signal output from a pressure sensor to determine a pumping phase of the high-pressure fuel pump and a pressure rise difference between a plurality of cylinders.

[0057] In another embodiment, the high frequency signal output from the pressure sensor is 10 kHz.

[0058] In an embodiment, the method includes overriding an engine speed limit at idle conditions while increasing fuel rail pressure during the diagnostic period.

[0059] In an embodiment, the pumping phase of the high pressure fuel pump is determined over a plurality of cycles of the engine before determining the pressure rise differential.

[0060] In an embodiment, the method is executed during an off-task service event.

[0061] According to another aspect of the present disclosure, an apparatus for testing a high-pressure fuel pump of an engine is provided. The apparatus includes a non-transitory memory medium configured to store instructions executable by a processor to: operate the high-pressure fuel pump during a diagnosis of the high-pressure fuel pump; receive a pressure sensor output indicating fuel pressure of a fuel rail during the diagnosis; determine a pressure rise differential between each of a plurality of cylinders of the high-pressure fuel pump based on the pressure sensor output during the diagnosis; and, in response to the pressure rise differential, display an operator-perceivable output indicating a condition of the high-pressure fuel pump and / or diagnose the condition of the high-pressure fuel pump.

[0062] In an embodiment, the instructions are executable by the processor to operate the high-pressure fuel pump without injecting fuel from the injector, and / or analyze the high-frequency signal output from the pressure sensor to determine the pumping phase of the high-pressure fuel pump and the pressure increase difference between the plurality of cylinders.

[0063] In another embodiment, the high frequency signal output from the pressure sensor is 10 kHz.

[0064] In an embodiment, the instructions are executable by the processor to perform the following actions: overriding an engine speed limit at idle conditions while increasing fuel rail pressure during a diagnostic period.

[0065] In an embodiment, the instructions are executable by the processor to perform the following actions: determining a pumping phase of the high pressure fuel pump over a plurality of cycles of the engine before determining the pressure rise differential.

[0066] In an embodiment, the instructions are configured to operate during an off-task service event.

[0067] In an embodiment, the instructions are configured to operate with an external diagnostic tool.

[0068] It should be understood that terms such as "non-transitory memory," "non-transitory memory medium," and "non-transitory memory device" refer to various types of devices and storage media that can be configured to store information, such as data or instructions, that can be read or executed by a processor or other component of a computer system, and that such terms include and encompass a single or unitary device or medium that stores such information, multiple devices or media across or in which respective portions of such information are stored, and multiple devices or media across or in which multiple copies of such information are stored.

[0069] It should be understood that when used in connection with a control method or process, an electronic control system or controller, an electronic control, or components or operations of the foregoing, terms such as "determine," "determined," "determining," and the like, inclusively refer to a plurality of actions, configurations, devices, operations, and techniques, including but not limited to estimating or calculating a parameter or value, obtaining a parameter or value from a lookup table or using a lookup operation, receiving a parameter or value from a data link or network communication, receiving an electronic signal (e.g., a voltage, frequency, current, or pulse width modulated (PWM) signal) indicative of a parameter or value, receiving a sensor output indicative of a parameter or value, receiving other output or input indicative of a parameter or value, reading a parameter or value from a memory location on a computer-readable medium, receiving a parameter or value as a run-time parameter, and / or by receiving a parameter or value that can be used to calculate an interpreted parameter, and / or by reference to a default value that is interpreted as a parameter value.

[0070] Although exemplary embodiments of the present disclosure have been shown and described in detail in the drawings and foregoing description, this is to be considered illustrative rather than restrictive in nature, and it is to be understood that only certain embodiments have been shown and described, and all changes and modifications that come within the spirit of the claimed invention are protected. It should be understood that while the use of words such as preferred, preferably, preferred, or more preferred utilized in the foregoing description indicates that the features so described may be more desirable, it may not be necessary and embodiments without such words are contemplated within the scope of the present invention, which scope is defined by the appended claims. When reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least a portion" are used, they are not intended to limit the claim to only one item, unless expressly stated to the contrary in the claim. When the language "at least a portion" and / or "a portion" is used, the item being described may include a portion and / or the entire item, unless expressly stated to the contrary.

Claims

1. A system comprising: an engine comprising a plurality of combustion chambers; a fuel supply system comprising a fuel rail in fluid communication with a plurality of fuel injectors, each of the plurality of fuel injectors being configured to provide fuel to a respective combustion chamber of the plurality of combustion chambers, and a high-pressure fuel pump in fluid communication with the fuel rail, the high-pressure fuel pump comprising a plurality of cylinders; and an electronic control system in operative communication with the fuel delivery system and configured to: operating the high-pressure fuel pump during diagnosis of the high-pressure fuel pump, receiving a pressure sensor output indicative of fuel pressure of the fuel rail during the diagnostic period, determining a pressure increase difference between each of the plurality of cylinders of a high pressure fuel pump based on the pressure sensor output during the diagnosis, and In response to the differential pressure increase, an operator-perceptible output indicative of a condition of the high-pressure fuel pump is displayed and / or the condition of the high-pressure fuel pump is diagnosed.

2. The system of claim 1 , wherein the electronic control system is configured to: operate the high-pressure fuel pump without injecting fuel from the injector, and / or analyze a high-frequency signal output from the pressure sensor to determine a pumping phase of the high-pressure fuel pump and the pressure increase difference between the plurality of cylinders.

3. The system of claim 2, wherein the high frequency signal output from the pressure sensor is 10 kHz. 4 . The system of claim 1 , wherein the electronic control system is configured to override an engine speed limit at idle conditions while increasing the fuel rail pressure during the diagnostic period.

5. The system of claim 1 , wherein the electronic control system is configured to: receive a pressure sensor output indicative of the fuel pressure of the fuel rail and determine a pumping phase of the high pressure fuel pump over a plurality of cycles of the engine before determining the pressure rise differential.

6. The system of any one of claims 1 to 5, wherein the electronic control system is operatively coupled to an external diagnostic tool.

7. The system of any one of claims 1 to 5, wherein the fuel rail is a high pressure common rail fuel connected to the high pressure fuel pump.

8. A method of controlling an engine fuel supply system, the engine fuel supply system comprising a fuel rail in fluid communication with a plurality of fuel injectors and a high pressure fuel pump in fluid communication with the fuel rail, each of the plurality of fuel injectors being configured to provide fuel to a corresponding combustion chamber of a plurality of combustion chambers, the method comprising: operating the high-pressure fuel pump during diagnosis of the high-pressure fuel pump, receiving a pressure sensor output indicative of fuel pressure of the fuel rail during the diagnostic period, determining a pressure increase difference between each of a plurality of cylinders of a high pressure fuel pump based on the pressure sensor output during the diagnosis, and In response to the differential pressure increase, an operator-perceptible output indicative of a condition of the high-pressure fuel pump is displayed and / or the condition of the high-pressure fuel pump is diagnosed.

9. The method of claim 8, further comprising: The high-pressure fuel pump is operated without injecting fuel from the injector, and / or a high-frequency signal output from the pressure sensor is analyzed to determine a pumping phase of the high-pressure fuel pump and the pressure increase differences among the plurality of cylinders.

10. The method of claim 9, wherein the high frequency signal output from the pressure sensor is 10 kHz.

11. The method of claim 8, further comprising: An engine speed limit at idle conditions is overridden during the diagnostic period while increasing the fuel rail pressure. 12 . The method of claim 8 , wherein the pumping phase of the high pressure fuel pump is determined over a plurality of cycles of the engine before determining the pressure rise difference.

13. The method of any one of claims 8 to 12, wherein the method is performed during an off-task service event.

14. An apparatus for testing a high-pressure fuel pump of an engine, the apparatus comprising: A non-transitory memory medium configured to store instructions executable by a processor to: operating the high-pressure fuel pump during diagnosis of the high-pressure fuel pump, receiving a pressure sensor output indicative of fuel pressure of a fuel rail during said diagnostic period, determining a pressure increase difference between each of a plurality of cylinders of a high pressure fuel pump based on the pressure sensor output during the diagnosis, and In response to the differential pressure increase, an operator-perceptible output indicative of a condition of the high-pressure fuel pump is displayed and / or the condition of the high-pressure fuel pump is diagnosed.

15. The apparatus of claim 14, wherein the instructions are executable by the processor to: The high-pressure fuel pump is operated without injecting fuel from the injector, and / or a high-frequency signal output from the pressure sensor is analyzed to determine a pumping phase of the high-pressure fuel pump and the pressure increase differences among the plurality of cylinders.

16. The apparatus of claim 15, wherein the high frequency signal output from the pressure sensor is 10 kHz.

17. The apparatus of claim 14, wherein the instructions are executable by the processor to: An engine speed limit at idle conditions is overridden during the diagnostic period while increasing the fuel rail pressure.

18. The apparatus of claim 14, wherein the instructions are executable by the processor to: Before determining the pressure increase difference, a pumping phase of the high-pressure fuel pump is determined over a plurality of cycles of the engine.

19. The apparatus of any one of claims 14 to 18, wherein the instructions are configured to operate during an off-task service event.

20. The apparatus of any one of claims 14 to 18, wherein the instructions are configured to operate with an external diagnostic tool.

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