Fuel leak detection system

Abstract

Fuel leak detection systems and methods are disclosed. A method for detecting a fuel leak of a fuel system of an engine includes detecting a ramp-up of the engine. The method includes measuring a rail pressure of a fuel rail during the ramp-up. The method also includes determining that a fuel leak is present in the fuel system based on the rail pressure measured during the ramp-up. In accordance with the determination that the fuel leak is present, the method includes outputting an indication of the fuel leak in the fuel system.

Description

Technical Field

[0001] The present invention relates generally to fuel systems in internal combustion engines, and more specifically to fuel leak detection systems for such fuel systems. Background Technology

[0002] Fuel systems used in internal combustion engines, such as high-pressure fuel systems, can leak over time for various reasons. For example, mechanical joints in the fuel lines of the fuel system may wear out, and fuel may leak through these joints. Such fuel systems can be designed to pump fuel to a common fuel rail, maintaining the rail pressure at a desired level. This ensures that the fuel rail is adequately pressurized for the engine's given needs when fuel is injected from the rail to the cylinders via one or more injectors. However, when leaks exist in the fuel system to meet the engine's demands, the pump's lifespan may be reduced, and the pump may eventually fail due to cavitation damage. Current leak detection methods can only detect relatively large leaks, requiring engine deceleration when a leak is detected. Therefore, current leak detection methods may be insufficient to detect moderate or relatively small leaks and / or may misdiagnose leaks in the fuel system.

[0003] U.S. Patent Application Publication No. 2014 / 0238352 (“'352 Publication”), published August 28, 2014, describes an electronic controller for a common rail fuel system that detects faults, such as leaks, when time and accumulated errors exceed thresholds. When operating conditions are transient (e.g., during ramp-up), time and accumulated errors remain constant, and are added to or subtracted from in response to rail pressure errors and whether operating conditions are steady-state. For example, time and accumulated errors are added to or subtracted from each other based on whether the rail pressure is greater than or less than a desired rail pressure during steady-state conditions. However, the '352 Publication is insufficient for detecting fuel leaks and / or moderate or relatively small leaks in fuel systems with recycle leaking fuel.

[0004] The fuel leak detection system of the present invention solves one or more of the problems described above and / or other problems in the art. However, the scope of the invention is defined by the appended claims, and not by its ability to solve any particular problem. Summary of the Invention

[0005] On one hand, a method for detecting fuel leakage in the fuel system of an engine is disclosed. The method includes: detecting a ramp-up of the engine; measuring the rail pressure of the fuel rail during the ramp-up; determining the presence of a fuel leakage in the fuel system based on the rail pressure measured during the ramp-up; and outputting an indication of the fuel leakage in the fuel system based on the determination of the presence of a fuel leakage.

[0006] In another aspect, a fuel leak detection system is disclosed. The system includes: a fuel system of an engine including a fuel rail; a sensor for measuring the rail pressure of the fuel rail; and a controller configured to: detect an accelerator lift of the engine; measure the rail pressure of the fuel rail during the accelerator lift; determine the presence of a fuel leak in the fuel system based on the rail pressure measured during the accelerator lift; and output an indication of the fuel leak in the fuel system based on the determination of the presence of a fuel leak.

[0007] In another aspect, a method for detecting fuel leakage in an engine's fuel system is disclosed. The method includes: detecting engine ramping when the fuel rail pressure exceeds a threshold value derived from idling conditions; measuring the fuel rail pressure during ramping; comparing the measured rail pressure during ramping with a desired rail pressure; determining whether the difference between the measured rail pressure and the desired rail pressure is greater than a threshold value; determining, based on the determination that the difference is greater than the threshold value, that a fuel leakage exists in the fuel system; and outputting an indication of fuel leakage in the fuel system. Attached Figure Description

[0008] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the specification, serve to explain the principles of the disclosed embodiments.

[0009] Figure 1 This is a schematic diagram of an engine system with a fuel leak detection system according to an aspect of the present invention.

[0010] Figure 2 It is used for Figure 1 A schematic diagram of an exemplary fuel leak detection system for an engine system.

[0011] Figure 3 A description is provided for detection. Figure 1 A flowchart illustrating an exemplary method for preventing fuel leakage in a system. Detailed Implementation

[0012] The foregoing general description and the following detailed description are merely exemplary and illustrative and do not limit the claimed features. As used herein, the terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” or other variations thereof are intended to cover non-exclusive inclusions, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but may also include other elements not expressly listed or inherent to such process, method, article, or apparatus. In this invention, unless otherwise stated, relative terms (e.g., “about,” “substantially,” and “approximately,” etc.) are used to indicate possible variations of ±10% in the stated values.

[0013] Figure 1 A schematic diagram of an engine system 10 with a fuel leak detection system 100 is shown. The engine system 10 includes an engine 12, such as an internal combustion engine. The engine 12 may include, for example, a diesel engine, a gasoline engine, a dual-fuel engine (e.g., an engine capable of operating on gaseous and / or liquid fuels), or any other type of engine known in the art. Operation of the engine 12 can generate power. For example, the engine 12 may include one or more cylinders (not shown) and a crankshaft (not shown) for providing power to a flywheel (not shown), etc. Figure 1 As shown, the engine system 10 also includes a fuel system 14, a common fuel rail 16, a fuel leak detection system 100, and an output indicator 18.

[0014] Fuel system 14 may include fuel supply 20, such as a fuel tank, pump 22, and common fuel rail 16, which are interconnected via fuel supply lines 24. Common fuel rail 16 may be fluidly coupled to one or more fuel injectors 26 for injecting liquid fuel into the cylinders of engine 12. Pump 22 may be a high-pressure pump for supplying fuel from supply source 20 to common fuel rail 16 at high pressure. Pump 22 may include a mechanical pump for compressing and pressurizing fluids (e.g., fuel) to high pressure. Pump 22 may include one or more valves (not shown), such as inlet metering valves, outlet metering valves, and / or any other type of valve known in the art, for ensuring that only the desired amount of fuel is supplied to common fuel rail 16. Fuel not consumed by the cylinders of engine 12 may be diverted back to supply source 20 for recirculation through fuel system 14. Furthermore, fuel supply lines 24 may include one or more leakage paths (not shown) such that leaked fuel in fuel system 14 is diverted back to supply source 20 for pumping through fuel system 14 (e.g., to rail 16). The fuel system 14 may also include a filter (not shown) and a low-pressure pump (not shown), such as a fuel delivery pump, between the fuel supply source 20 and the pump 22 for generating a fuel flow from the supply source 20 to the pump 22. It should be understood that the fuel system 14 may include any number and / or combination of valves or other components known in the art.

[0015] Output indicator 18 can indicate a fuel leak in fuel system 14, as detailed below. Output indicator 18 may include a display, instrument, light, speaker, etc. For example, output indicator 18 may indicate the value (numerical value, percentage, etc.) of leaking fuel in fuel system 14 and / or indicate (e.g., by notification) when a fuel leak is present in fuel system 14. Indicator 18 may be located in the operator's cab (not shown) and / or may be positioned away from engine system 10. Although only a single output indicator 18 is described herein, it should be understood that output indicator 18 may include one or more indicators and may include any type of indicator for indicating a fuel leak in fuel system 14.

[0016] The fuel leak detection system 100 includes a controller 104, such as an engine control module (ECM), and a sensor system 30 connected to the controller 104. The sensor system 30 may include one or more sensors for measuring engine operating conditions, such as pressure sensors, flow sensors, speed sensors, etc. For example, the sensor system 30 may include a rail pressure sensor 32. The rail pressure sensor 32 may be located in the common fuel rail 16 and can sense rail pressure. It should be understood that the sensor 32 may include any type of sensor, such as a resistive sensor, an inductive sensor, a capacitive sensor, a piezoelectric sensor, an optical sensor, a microelectromechanical system (MEMS) sensor, etc. Although not shown, the sensor system 30 may include other sensors for measuring engine operating conditions, including, for example, a flow sensor (e.g., a flow meter) for measuring the flow rate of fuel from pump 22, a speed sensor (e.g., a tachometer) for measuring the speed of engine 12, a torque sensor for measuring the torque generated by engine 12, and / or any other sensors known in the art. Furthermore, the sensor system 30 may include any number and / or combinations of sensors as needed. The controller 104 can also be connected to the pump 22 to control the position of the valve of the pump 22, and to the injector 26 to regulate and control the fuel pressure in the rail 16 and the fuel injection into the cylinder of the engine 12.

[0017] Figure 2 A schematic diagram of an exemplary fuel leak detection system 100 for operating and / or controlling at least a portion of an engine system 10 is shown. System 100 may include an input 102, a controller 104, and an output 106. Input 102 may include, for example, a rail pressure signal 110 from a pressure sensor 32. Output 106 may include, for example, a fuel leak indication signal 112. Controller 104 also includes a fuel leak detection module 108. Fuel leak detection module 108 may receive input 102, implement a method 300 for detecting fuel leaks in fuel system 14, and control output 106, as shown below. Figure 3 As stated above.

[0018] The controller 104 may be embodied as a single microprocessor or multiple microprocessors, and may include means for detecting fuel leaks in the fuel system 14 of the engine system 10. For example, the controller 104 may include memory, auxiliary storage, a processor such as a central processing unit, or any other means for performing tasks consistent with the present invention. The memory or auxiliary storage associated with the controller 104 may store information that helps the controller 104 perform its functions (e.g., ...). Figure 3The controller 104 may contain data and / or software routines (the functions of method 300). Furthermore, a memory or auxiliary storage device associated with the controller 104 may store data received from various inputs 102 associated with the fuel leak detection system 100. Many commercially available microprocessors can be configured to perform the functions of the controller 104. It should be understood that the controller 104 can be readily embodied as a general-purpose machine controller capable of controlling many other machine functions. Furthermore, the controller 104 or portions thereof may be located remotely from the engine system 10. Various other known circuits may be associated with the controller 104, including signal conditioning circuits, communication circuits, hydraulic or other actuation circuits, and other suitable circuits.

[0019] Controller 104 may also include stored values ​​used by module 108. For example, the stored values ​​may include ramp-up condition thresholds, desired rail pressure maps, and rail pressure difference thresholds. Ramp-up condition thresholds may include one or more thresholds for various operating conditions of engine system 10 that indicate ramp-up of engine system 10. As used herein, “ramp-up” is a change and / or increase in engine operating conditions from idle conditions to steady-state conditions (e.g., to a desired value for the corresponding operating condition). In other words, ramp-up may include transient conditions of operating conditions. For example, ramp-up condition thresholds may include rail pressure thresholds (e.g., 50 MPa) such that ramp-up exists when rail pressure increases above the threshold from idle conditions to steady-state conditions (e.g., for a given operating condition to the final desired rail pressure). Thus, ramp-up may include an increase between the threshold and the desired rail pressure in the steady-state state. Idle conditions exist when engine operating conditions are below their respective ramp-up thresholds for a predetermined amount of time. For example, idle conditions may exist when rail pressure is less than 50 MPa for a predetermined amount of time. Ramp-up condition thresholds and idle condition thresholds may also include thresholds for engine speed, engine load, idle time, pump flow rate, or any other parameter indicating engine operating conditions. As used herein, “engine load” can be the ability of engine system 10 to generate power (e.g., torque) relative to rated or maximum load at various speeds of engine system 10. Controller 104 can determine or derive engine load from various inputs, including, for example, intake manifold pressure, torque generated by engine system 10, speed of engine system 10, amount of liquid fuel injected into cylinders of engine 12, or any other input. Module 108 can determine the presence of a ramp-up condition when a corresponding engine operating condition parameter exceeds the corresponding ramp-up condition threshold from an idle condition, as described in further detail below. Furthermore, it should be understood that module 108 can utilize ramp-up thresholds for a single parameter (e.g., rail pressure), and / or can utilize multiple (e.g., more than one) ramp-up thresholds in combination for various parameters.

[0020] The desired rail pressure diagrams can provide predetermined, expected, or required values ​​of rail pressure for various operating conditions of engine system 10. These diagrams or lookup tables can plot two or more operating conditions to provide the desired rail pressure output for the corresponding operating condition. For example, these desired rail pressure diagrams can provide the desired rail pressure based on engine speed, engine load, fuel ratio, or any other engine operating condition. The information used to derive the values ​​of the diagrams or lookup tables can be determined through empirical analysis. Such empirical data can be obtained, for example, by operating test engine system 10 under predetermined conditions (e.g., under specific operating conditions) during, for example, bench testing. For example, the desired rail pressure value can be correlated with the value of the engine operating condition. It should be understood that the diagrams or lookup tables can provide the desired rail pressure value as a function of any type of input as needed. Furthermore, the desired rail pressure diagrams can provide the expected rate of increase in rail pressure to reach the desired rail pressure. For example, during ramp-up, the desired rail pressure can increase at the expected rate of increase to reach the desired rail pressure for steady state, as described in further detail below.

[0021] The rail pressure differential threshold may include one or more thresholds representing the difference between the measured or actual rail pressure and the desired rail pressure during a climb, indicating fuel leakage in the fuel system 14. For example, during a climb event, a time lag may exist between the desired rail pressure and the measured or actual rail pressure until the actual rail pressure is substantially equal to the desired rail pressure under steady-state conditions (e.g., when the actual rail pressure reaches the desired rail pressure by a predetermined amount of time). When there is demand on the engine system 10, a time lag may exist due to the delay in pumping fuel to the rail 16 by the pump 22 when the injector 26 injects fuel from the rail 16 to meet the desired rail pressure. For example, the pump 22 may pump fuel to the rail 16 to maintain the actual rail pressure at the desired rail pressure during steady-state conditions. Therefore, when there is a demand on engine system 10, such as when the operator actuates the accelerator, the desired rail pressure can immediately increase to the desired rail pressure for a given operating condition, and pump 22 can pump fuel to rail 16 to meet the desired rail pressure for that demand when injector 26 injects fuel from rail 16 into the cylinders of engine 12. A delay may exist due to the time spent by pump 22 in response to demand to pump fuel and pressurize rail 16. However, if there is a fuel leak in fuel system 14, the time lag for a given demand may be greater than the desired time lag, or the desired rail pressure increase. Therefore, if the difference between the measured or actual rail pressure during ramp and the desired rail pressure is greater than one or more rail pressure difference thresholds, there may be a fuel leak in fuel system 14. Furthermore, the rail pressure difference thresholds may depend on the given engine platform (e.g., engine type) and engine operating type (e.g., constant speed engine, variable speed engine, load and speed profile for a given engine). The rail differential pressure threshold can provide a single static value (e.g., 10 MPa) for a given application and / or can provide variable values ​​based on operating conditions and / or various types of ramp profiles for different requirements of the engine system 10 (e.g., a first value for a first set of operating conditions and a second value for a different second set of operating conditions).

[0022] The rail differential threshold may also provide other values ​​indicating fuel leakage in fuel system 14. For example, the rail differential threshold may provide a rate of increase or time threshold for the measured or actual rail pressure to meet or substantially equal the desired rail pressure in a steady state (e.g., at the desired rail pressure), or a rate of increase or time threshold for the measured or actual rail pressure to reach a steady state after ramp conditions. For example, when there is no leakage or the leakage is negligible in fuel system 14, the measured or actual rail pressure may reach a steady state and / or substantially equal the desired rail pressure after a relatively short amount of time. When a leakage is present in fuel system 14, the rate of increase of the measured or actual rail pressure will be less than the expected rate of increase, such that the time it takes for the measured or actual rail pressure to meet the desired rail pressure in a steady state is greater than the time threshold (e.g., the expected time). It should be understood that the rail differential threshold may include any other value or threshold indicating the difference in fuel leakage in fuel system 14.

[0023] Fuel leak indication signal 112 may include control of various aspects of engine system 10. For example, fuel leak indication signal 112 may include a controller 104 output signal to display a value indicating a fuel leak in fuel system 14 on an output indicator 18 (e.g., on a display). Fuel leak indication signal 112 may also include the controller 104 outputting an alarm, such as a light, audible alarm, or display alarm, when a fuel leak is present in fuel system 14. Fuel leak indication signal 112 may also include mitigation or remediation recommendations. For example, module 108 may recommend service intervals, fuel system testing, and / or any other maintenance techniques for locating, mitigating, and / or remediating a fuel leak in fuel system 14. Fuel leak indication signal 112 may also include a controller 104 that regulates engine system 10. For example, controller 104 may reduce or shut down engine system 10 or parts thereof.

[0024] Industrial applicability

[0025] The disclosed aspects of the fuel leak detection system 100 of the present invention can be used in any engine system 10 having a pump 22.

[0026] Reference Figure 1During operation of engine system 10, pump 22 of fuel system 14 can draw fuel from fuel supply source 20. Pump 22 then supplies pressurized fuel to rail 16 via supply line 24. The pressurized fuel can be maintained at a pressure in rail 16 by pump 22, as described in detail above. The pressurized fuel can then be injected into cylinders of engine 12 via injector 26, and the combustion of fuel (and air) in the cylinders can cause rotation of the crankshaft to provide useful mechanical power. In some cases, fuel leakage may occur in fuel system 14. For example, mechanical joints between rail 16, supply line 24, and / or injector 26 may wear and fuel may leak through these joints. As described above, leaked fuel in fuel system 14 can be directed back to supply source 20, such that the leaked fuel is drawn from supply source 20 by pump 22. Thus, the leaked fuel is recirculated through fuel system 14 to rail 16, and therefore to injector 26. Furthermore, pump 22 can pressurize rail 16 to the desired rail pressure under steady-state conditions. In this situation, since pump 22 is controlled to meet the desired rail pressure during steady-state conditions, the measured or actual rail pressure can be substantially equal to the desired rail pressure during steady-state conditions. Therefore, leakage may not be adequately detected under steady-state conditions. Therefore, refer to the following... Figure 3 As described in detail, the fuel leak detection system 100 can detect fuel leaks in the fuel system 14 during the ramp-up of the engine system 10.

[0027] Figure 3 A flowchart depicting an exemplary method 300 for detecting fuel leakage in the fuel system 14 of engine system 10 is shown. In step 305, module 108 may detect ramp conditions of engine system 10. For example, module 108 may measure the rail pressure of rail 16 and detect ramp when the measured rail pressure and / or the desired rail pressure exceeds a threshold (e.g., 50 MPa) from idle conditions. As described above, module 108 may utilize other operating condition parameters and corresponding ramp thresholds. For example, module 108 may determine ramp based on engine speed (e.g., greater than 1,000 RPM), engine load (e.g., greater than 20%), and / or any other operating condition parameters, or combinations thereof, which increase from idle conditions and exceed a corresponding ramp threshold. Based on the determination that the corresponding operating conditions exceed the corresponding ramp threshold from idle conditions, module 108 may determine the ramp of engine system 10. It should be understood that module 108 may detect ramp conditions of engine system 10 by any other methods known in the art.

[0028] In step 310, when module 108 has detected the climb conditions of engine system 10, module 108 can measure the rail pressure of track 16 during the climb. For example, controller 104 can receive rail pressure signal 110 and determine or otherwise derive the rail pressure of track 16. Module 108 can also determine the rate of change of rail pressure over time based on rail pressure signal 110.

[0029] In step 315, module 108 can compare the measured rail pressure with the desired rail pressure. As detailed above, module 108 can determine the desired rail pressure from these desired rail pressure maps. For example, module 108 can determine the desired rail pressure for a given requirement of engine system 10 based on one or more operating conditions.

[0030] In step 320, module 108 may determine whether the difference between the measured rail pressure and the desired rail pressure of track 16 is greater than a threshold during the climb. For example, when there is no leakage or negligible leakage and the engine system 10 is climbing, the rail pressure of track 16 increases accordingly to the desired rail pressure in a steady state (e.g., to the desired rail pressure for a given operating condition) and / or the expected or desired rail pressure rate based on the operating conditions during the climb. In other words, the rail pressure of track 16 will increase to the desired rail pressure in a steady state within an expected or desired amount of time. Therefore, when the difference between the measured rail pressure and the desired rail pressure of track 16 is less than or equal to the threshold (step 320: No), module 108 may repeat method 300 and continue to detect the climb conditions (step 305).

[0031] When a fuel leak is present in fuel system 14, the rail pressure of track 16 may not increase accordingly to the desired rail pressure and / or increase at the desired rail pressure rate based on operating conditions during the climb. In other words, the rail pressure of track 16 will increase to the desired rail pressure or steady state over a longer period of time than expected. Therefore, in step 325, based on the determination that the difference between the measured rail pressure and the desired rail pressure of track 16 is greater than a threshold (step 320: Yes), module 108 may output an indication of a fuel leak in fuel system 14. For example, module 108 may display the indication of a fuel leak on output indicator 18 (e.g., on a display and / or as a notification, such as a light, audible alarm, alarm on the display, etc.). Module 108 may then repeat method 300 and continue to detect climb conditions (step 305).

[0032] In some embodiments, module 108 may store the difference or instances of difference between the measured rail pressure and the desired rail pressure. For example, module 108 may detect several different ramp events and store the differences between the different ramp events. Therefore, module 108 may generate a distribution of the differences between the different ramp events over time. For example, this distribution may include a graphical representation of the difference for each different ramp event. Based on this distribution, module 108 may determine the average value of the differences between the different ramp events. If the average value is greater than a rail pressure difference threshold, module 108 may determine that a fuel leak exists in fuel system 14 and output an indication of a fuel leak, as described above. Therefore, by tracking the differences over multiple ramp events, false negatives and false positives in leak detection can be reduced or eliminated.

[0033] Fuel leak detection system 100 can provide an indication of fuel leaks in fuel system 14. For example, fuel leak detection system 100 can detect fuel leaks in pump 22, supply line 24, rail 16, injector 26, and / or any other component of fuel system 14. Furthermore, by detecting leaks during ramp events, fuel leak detection system 100 can detect moderate or relatively small fuel leaks. Therefore, even though fuel system 14 is designed to ensure that measured rail pressures reach (e.g., substantially equal to) the desired rail pressure during steady-state conditions, fuel leak detection system 100 can detect fuel leaks. Thus, fuel leak detection system 100 can detect fuel leaks in fuel system 14 more accurately or adequately and proactively alert users (e.g., operators, technicians, etc.) so that users can repair and / or replace the corresponding components to mitigate the fuel leak.

[0034] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system without departing from the scope of the invention. Other embodiments of the system will be apparent to those skilled in the art upon consideration of the practice of the specification and the methods disclosed herein. This specification and examples are intended to be considered merely exemplary, and the true scope of the invention is indicated by the appended claims and their equivalents.

Claims

1. A method for detecting fuel leakage in an engine's fuel system, comprising: Detect the tilt of the engine; The rail pressure of the fuel rail is measured during the ramp. A fuel leak was determined to be present in the fuel system based on rail pressure measurements taken during the ascent. as well as Based on the determination of a fuel leak, an indication of a fuel leak in the fuel system is output; The detection of the ramp includes detecting the ramp when the rail pressure exceeds a threshold from idle conditions; and, The determination of the presence of a fuel leak includes: The rail pressure measured during the ascent will be compared with the expected rail pressure; Determine whether the difference between the measured rail pressure and the expected rail pressure is greater than the rail pressure difference threshold; and Based on the determination that the difference is greater than the rail pressure difference threshold, it is determined that there is a fuel leak; Furthermore, the rail pressure differential threshold is a variable value.

2. The method of claim 1, wherein detecting the ramp further comprises detecting the ramp when one or more of the engine speed, engine load, or pump flow rate exceeds a threshold from an idle condition.

3. The method of claim 1, wherein determining the presence of a fuel leak comprises: Determine whether the time taken for the measured rail pressure to reach a steady state is greater than the expected time to reach a steady state. as well as The presence of a fuel leak is determined based on the fact that the time required to reach a steady state is longer than expected.

4. The method according to claim 1, further comprising: The presence of a fuel leak was determined based on rail pressure measurements taken during multiple ramps.

5. The method of claim 1, further comprising: Detect multiple ramps of the engine; For each of the plurality of ramps, store the difference between the measured rail pressure and the desired rail pressure; as well as A fuel leak is determined when the average of the differences among the plurality of ramps is greater than a threshold.

6. The method of claim 1, wherein outputting the indication of fuel leakage comprises: Generate recommendations for mitigating fuel leaks; as well as Output the aforementioned suggestions.

7. A fuel leak detection system, comprising: The fuel system for engines, including fuel rails; Sensors used to measure the rail pressure of the fuel rail; as well as The controller is configured as follows: Detect the tilt of the engine; Measure the rail pressure of the fuel rail during the ramp; A fuel leak was determined to exist in the fuel system based on the rail pressure measured during the ascent. as well as Based on the determination of a fuel leak, an indication of a fuel leak in the fuel system is output; The detection of the ramp includes the controller being configured to detect the ramp when the rail pressure exceeds a threshold from an idle condition; and The determination of the presence of a fuel leak includes: The rail pressure measured during the ascent will be compared with the expected rail pressure; Determine whether the difference between the measured rail pressure and the expected rail pressure is greater than the rail pressure difference threshold; and Based on the determination that the difference is greater than the rail pressure difference threshold, it is determined that there is a fuel leak; Furthermore, the rail pressure differential threshold is a variable value.

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