Failure diagnostic system for engine

• US 6,647,769 B1
• Filed: 10/25/2000
• Issued: 11/18/2003
• Est. Priority Date: 10/26/1999
• Status: Active Grant

• Current Assignee: Yamaha Marine Kabushiki Kaisha
• Original Assignee: Yamaha Marine Kabushiki Kaisha
• Inventors: Fujino, Kenichi, Motose, Hitoshi
• Primary Examiner(s): MCCALL, ERIC SCOTT
• Application Number:
  US09/696,060
• Time in Patent Office: 1,119 Days
• Field of Search: 731/16, 731/172, 731/173, 731/181, 731/19.A, 731/19.R
• US Class Current: 73/114.41
• CPC Class Codes: F02B 61/045 for outboard marine engines
• CPC Class Codes: F02B 77/08 Safety, indicating or supervising devices thermal insulation F02B77/11; rendering engines inoperative or idling F02D17/04; dependent on lubricating conditions F01M1/22; dependent on cooling F01P11/14
• CPC Class Codes: F02D 2041/224 Diagnosis of the fuel system
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2200/0414 Air temperature
• CPC Class Codes: F02D 2200/0602 Fuel pressure
• CPC Class Codes: F02D 41/1454 the characteristics being an oxygen content or concentration or the air-fuel ratio
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02D 41/3082 Control of electrical fuel pumps
• CPC Class Codes: F02D 41/3836 Controlling the fuel pressure
• CPC Class Codes: F02D 41/3863 by controlling the flow out of the common rail, e.g. using pressure relief valves
• CPC Class Codes: F02M 65/00 Testing fuel-injection apparatus, e.g. testing injection timing testing of ignition F02P17/00; measuring fuel consumption G01F9/00; Cleaning of fuel-injection apparatus

Abstract

A diagnostic system is provided for aiding a technician or engineer in verifying that a fuel injector in a fuel injected engine is operating properly. The diagnostic system comprises a controller operatively coupled to an actuator for the fuel injector and to a fuel pressure sensor. The controller is configured such that, during a fuel injector test, the controller outputs a signal to the fuel pump so that pressurized fuel is supplied to the fuel injector. After the pressurized fuel is supplied to the fuel injector, the controller outputs a signal to the actuator to operate the fuel injector for a predetermined amount of time. The controller is also configured such that after the predetermined amount of time the fuel pump is turned off.

Claims

1. A method for verifying operation of a fuel injector in a fuel injected engine, the engine comprising an electronic control unit that is operatively connected to an actuator configured to open and close the fuel injector and an electric fuel pump that supplies fuel to the fuel injector during normal engine operations, the method comprising:

operating the electric fuel pump;

operating the fuel injector while the engine is not in operation;

determining if the fuel injector has been operating for a specified amount of time;

stopping the operation of the fuel injector if the fuel injector has been operating for a predetermined amount of time; and

stopping the operation of the electric fuel pump.

2. The method of claim 1, wherein the predetermined amount of time at least is approximately equal to a minimum amount of time necessary for a technician to audibly verify the operation of the fuel injector.

3. The method of claim 1, wherein operating the electric fuel pump further includes operating the electric fuel pump so as to produce a fuel pressure at the fuel injector that is less than the fuel pressure at the fuel injector during normal outboard motor operations.

4. The method of claim 1, further comprising sensing a fuel pressure and determining if the fuel pressure is greater than a predetermined value.

5. The method of claim 4, wherein the fuel injector is operated only if the fuel pressure is greater than the predetermined value.

6. The method of claim 4, wherein the predetermined value is chosen so as to provide enough fuel to the fuel injector so as to prevent the fuel injector from overheating during the method for verifying the operation of the fuel injector.

7. The method of claim 1, further comprising connecting a controller to an outboard motor and removing a protective cowling that surrounds the engine.

20. The method of claim 1, wherein operating the electric fuel pump further includes operating the electric fuel pump so as to produce a fuel pressure at the fuel injector that is less than the fuel pressure at the fuel injector during normal engine operation.

21. The method of claim 4, wherein the predetermined value of pressure provides enough fuel to the fuel injector so as to prevent the fuel injector from overheating during the method for verifying the operation of the fuel injector.

8. A diagnostic system for aiding a technician or engineer in verifying that a fuel injector in a fuel injected engine is operating properly, the diagnostic system comprising

a controller operatively coupled to an actuator for the fuel injector and to a fuel pressure sensor, the controller being configured such that, during a fuel injector test, the controller outputs a signal to an electric fuel pump that supplies fuel to the engine during normal engine operation so that pressurized fuel is supplied to the fuel injector and after pressurized fuel is supplied to the fuel injector the controller outputs a signal to the actuator to operate, the fuel injector for a predetermined amount of time while the electric fuel pump continues to operate, the controller also being configured such that after the predetermined amount of time the electric fuel pump is turned off.

9. The diagnostic system of claim 8, wherein the predetermined amount of time at least is approximately equal to a minimum amount of time for a technician to audibly verify the operation of the fuel injector.

10. The diagnostic system of claim 8, wherein the controller is furthered configured to send a signal to the electric fuel pump such that a fuel pressure at the fuel injector is less than the fuel pressure at the fuel injector during normal outboard motor operations.

11. The diagnostic system of claim 8, wherein the controller is further configured to receive a signal from a fuel pressure sensor indicating a fuel pressure and determine if the fuel pressure is greater than a predetermined value.

12. The diagnostic system of claim 11, wherein the controller is further configured to operate the fuel injector after the fuel pressure is greater than a predetermined value.

13. The diagnostic system of claim 11, wherein the predetermined value is chosen so as to provide enough fuel to the fuel injector to prevent the fuel injector from overheating during the fuel injector test.

22. The diagnostic system of claim 8, wherein the controller is furthered configured to send a signal to the electric fuel pump such that a fuel pressure at the fuel injector is less than the fuel pressure at the fuel injector during normal engine operation.

23. The diagnostic system of claim 11, wherein the predetermined value of pressure provides enough fuel to the fuel injector to prevent the fuel injector from overheating during the fuel injector test.

25. The diagnostic system of claim 8, wherein the actuator for the fuel injector is an electronic control unit configured to collect and store engine operational data.

26. The diagnostic system of claim 25, wherein the controller is configured to retrieve the engine operational data stored in the electronic control unit.

14. A method for verifying operation of a fuel injector in a fuel injected engine, the engine comprising an electronic control unit that is operatively connected to an actuator configured to open and close the fuel injector and an electric fuel pump that supplies fuel to the fuel injector during normal engine operations, the method comprising:

operating the fuel injector while the engine is not in operation;

passing fuel through the fuel injector, while the engine is not in operation, at a reduced fuel pressure in comparison to the fuel pressure present in the fuel injector when the engine is in operation; and

stopping the operation of the fuel injector after the fuel injector has been operating for a predetenmined amount of time.

15. The method of claim 14, wherein the predetermined amount of time is at least approximately equal to a minimum amount of time necessary for a technician to audibly verify the operation of the fuel injector.

16. The method of claim 14, further comprising sensing a fuel pressure and determining if the fuel pressure is greater than a predetermined value.

17. The method of claim 16 wherein the fuel injector is operated only if the fuel pressure is greater than the predetermined value.

18. The method of claim 16, wherein the predetermined value is chosen so as to provide enough fuel to the fuel injector so as to prevent the fuel injector from overheating during the method for verifying the operation of the fuel injector.

19. The method of claim 14, further comprising connecting a controller to an outboard motor and removing a protective cowling that surrounds the engine.

24. The method of claim 16, wherein the predetermined value of pressure provides enough fuel to the fuel injector so as to prevent the fuel injector from overheating during the method for verifying the operation of the fuel injector.

27. A method for verifying operation of a fuel injector in a fuel injected engine, the engine comprising an electronic control unit that is operatively connected to an actuator configured to open and close the fuel injector and an electric fuel pump that supplies fuel to the fuel injector during normal engine operations, the method comprising:

maintaining a pressure in a portion of the fuel system with an electric fuel pump;

operating the fuel injector while the pressure is maintained in the fuel system and while the engine is not in operation;

determining if the fuel injector has been operating for a specified amount of time;

stopping the operation of the fuel injector if the fuel injector has been operating for a predetermined amount of time; and

stopping the operation of the electric fuel pump after determining that the fuel injector has been operating for the specified amount of time.