Claims
- 1. A method for controlling a fuel system and detecting faults within said fuel system, the fuel system including at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating the liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state, the method comprising the steps of:
(a) controlling power supplied to the heat source of the at least one fuel injector to achieve a predetermined target temperature, the predetermined target temperature operable to convert a portion of liquid fuel to the vapor state; (b) setting a resistance value, the resistance value relatable to the predetermined target temperature; (c) determining if said resistance value is outside of a predetermined range; (d) if said resistance value is outside of a predetermined range, issuing a fault detection signal.
- 2. The method of claim 1 wherein the lower end of said predetermined range for said resistance value is unity.
- 3. The method of claim 1 wherein the higher end of said predetermined range is 1.25.
- 4. The method of claim 1 wherein the fuel system is installed in a vehicle and said fault detection signal causes a vehicle check engine light to illuminate.
- 5. The method of claim 1 wherein said heat source comprises a binary power source.
- 6. The method of claim 1 wherein said heat source comprises a proportional integral derivative controller.
- 7. The method of claim 1 wherein the fuel system is installed in a vehicle and the fault detection signal initiates the step of terminating power supplied to the heat source of the at least one fuel injector until the vehicle is serviced.
- 8. The method of claim 1 further comprising the step of adjusting said resistance value as a result of physical changes to said capillary flow passage over time.
- 9. The method of claim 1 wherein said step of adjusting said resistance value as a result of physical changes to said capillary flow passage over time comprises the following sub-steps:
(a) measuring a value indicative of degree of engine warm-up; (b) in the event that said value indicative of degree of engine warm-up is below a predetermined level then performing the following steps; (c) measuring the cold resistance value for said capillary flow passage; (d) measuring the intake ambient temperature; (e) determining if either said measured cold resistance value or said measured intake ambient temperature value matches previously stored measurement for each of said values respectively; (f) in the event neither said measured cold resistance value or said measured intake ambient temperature value matches the previously stored measurement for each of said values respectively, then adjusting a resistance value, said resistance value relatable to a predetermined target temperature for said capillary flow passage.
- 10. A method for controlling a fuel system and detecting faults within said fuel system, the fuel system including at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating the liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state, the method comprising the steps of:
(a) controlling power supplied to the heat source of the at least one fuel injector to achieve a predetermined target temperature, the predetermined target temperature operable to convert a portion of liquid fuel to the vapor state; (b) measuring the time necessary to heat said capillary flow passage to said predetermined target temperature; and (c) if said time to heat said capillary flow passage to said predetermined target temperature is outside of a predetermined range, issuing a fault detection signal.
- 11. The method of claim 10 wherein said time measurement is initiated upon activation of the key-on signal.
- 12. The method of claim 10 wherein the fuel system is installed in a vehicle and said fault detection signal causes a vehicle check engine light to illuminate.
- 13. The method of claim 10 wherein said heat source comprises a binary power source.
- 14. The method of claim 10 wherein said heat source comprises a proportional integral derivative controller.
- 15. The method of claim 10 wherein the fuel system is installed in a vehicle and the fault detection signal initiates the step of terminating power supplied to the heat source of the at least one fuel injector until the vehicle is serviced.
- 16. A fuel system for use in an internal combustion engine, comprising:
(a) a plurality of fuel injectors, each injector including at least one capillary flow passage, said at least one capillary flow passage having an inlet end and an outlet end; (b) a heat source arranged along the at least one capillary flow passage, the heat source operable to heat liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state; (c) a valve for metering fuel to the internal combustion engine; (d) a controller to control the power supplied to the heat source of each of is the plurality of fuel injectors to achieve a predetermined target temperature; (e) a sensor for use in determining engine air flow; and (f) a sensor for measuring a value indicative of degree of engine warm-up of the internal combustion engine; wherein the fuel system is capable of detecting system faults and responding thereto.
- 17. The fuel system of claim 16 wherein the power supplied to the heat source is controlled by setting a resistance value, the resistance value relatable to the predetermined target temperature and the controller is operable to determine if the resistance value is outside of a predetermined range.
- 18. The fuel system of claim 17 wherein, in the event that the resistance value is outside of a predetermined range, said controller issues a fault detection signal.
- 19. The fuel system of claim 18 wherein the fuel system is installed in a vehicle and the fault detection signal causes a vehicle check engine light to illuminate.
- 20. The fuel system of claim 19 wherein the fuel system is installed in a vehicle and the fault detection signal terminates power supplied to said heat source of said plurality of fuel injectors until the vehicle is serviced.
RELATED APPLICATION
[0001] This patent application is a continuation-in-part of application Ser. No. 10/284,180, filed on Oct. 31, 2002 directed to a FUEL SYSTEM FOR AN INTERNAL COMBUSTION ENGINE AND METHOD FOR CONTROLLING SAME, which is a continuation-in-part of application Ser. No. 10/143,250, filed on May 10, 2002, directed to a FUEL INJECTOR FOR AN INTERNAL COMBUSTION ENGINE, which are hereby incorporated by reference.
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
10284180 |
Oct 2002 |
US |
Child |
10410957 |
Apr 2003 |
US |
Parent |
10143250 |
May 2002 |
US |
Child |
10284180 |
Oct 2002 |
US |