Leaky injector mitigation action for vehicles during idle stop

Patent metadata

Field	Value
Publication number	US-10161344-B2
Application number	US-201514845018-A
Country	US
Kind code	B2
Filing date	Sep 3, 2015
Priority date	Sep 3, 2015
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

Methods and systems are provided for mitigating the effects of a leaky fuel injector during vehicle idle stop conditions. In one example, a method may include identifying the cylinder with a leaky fuel injector, and at or during engine shutdown, positioning the engine to a selected position based on the identified cylinder such that an exhaust valve of the identified cylinder is at least partly open.

First claim

The invention claimed is:

1. A method comprising:
identifying a cylinder of an engine with a fuel injector leak; and
at or after engine shutdown, positioning the engine to a selected engine position based on the identified cylinder such that an exhaust valve of the identified cylinder is at least partly open.

2. The method of claim 1 , wherein positioning the engine to the selected engine position comprises positioning the engine during non-combusting, non-engine driving conditions.

3. The method of claim 1 , wherein positioning the engine to the selected position comprises rotating the engine with an electric motor to remain stopped at the selected engine position where the exhaust valve of the identified cylinder is at least partly open.

4. The method of claim 3 , wherein rotating the engine with the electric motor to the selected engine position comprises rotating the engine with the electric motor responsive to the engine coming to a rest.

5. The method of claim 3 , wherein rotating the engine with the electric motor to the selected engine position comprises determining a first amount of forward rotation to reach the selected engine position, determining a second amount of reverse rotation to reach the selected engine position, and rotating the engine with the electric motor with either the first amount of forward rotation or the second amount of reverse rotation.

6. The method of claim 5 , wherein when the first amount is greater than the second amount, the engine is rotated with the second amount of reverse rotation, and when the first amount is less than the second amount, the engine is rotated with the first amount of forward rotation.

7. The method of claim 3 , wherein rotating the engine with the electric motor comprises only rotating the engine with the electric motor when a battery state of charge is above a threshold charge.

8. The method of claim 1 , further comprising initiating an idle engine stop responsive to one or more of engine speed, brake pedal position, and accelerator pedal position, and wherein positioning the engine to the selected engine position comprises positioning the engine at or after the idle engine stop is initiated.

9. A method for an engine having a plurality of cylinders, comprising:
identifying a cylinder of the plurality of cylinders of the engine having a fuel injector leak;
during engine operation, adjusting an amount of fuel supplied to one or more cylinders of the plurality of cylinders of the engine; and
at or after engine shutdown, positioning the engine to a selected engine position based on the identified cylinder such that an exhaust valve of the identified cylinder is at least partly open.

10. The method of claim 9 , wherein adjusting an amount of fuel supplied to one or more remaining cylinders of the plurality of cylinders of the engine comprises:
determining an amount of fuel leaked into the identified cylinder during an engine cycle; and
reducing an amount of fuel supplied to the one or more remaining cylinders during a subsequent engine cycle by an amount corresponding to the amount of fuel leaked into the identified cylinder.

11. The method of claim 10 , wherein determining the amount of fuel leaked into the identified cylinder during the engine cycle comprises determining the amount of fuel leaked into the identified cylinder during the engine cycle based on output from an exhaust oxygen sensor.

12. The method of claim 10 , wherein determining the amount of fuel leaked into the identified cylinder during the engine cycle comprises determining the amount of fuel leaked into the identified cylinder during the engine cycle based on a change in oxygen storage capacity of a catalyst positioned downstream of the engine during the engine shutdown, and wherein the change in oxygen storage capacity is determined based on a difference between a first oxygen storage capacity of the catalyst at a subsequent engine start-up and a second oxygen storage capacity of the catalyst at a prior engine start-up before the identification of the cylinder having the fuel injector leak.

13. The method of claim 12 , further comprising, during an engine start-up event following the engine shutdown, adjusting an engine air-fuel ratio based on the change in oxygen storage capacity of the catalyst.

14. The method of claim 9 , wherein adjusting the amount of fuel supplied to one or more cylinders of the plurality of cylinders of the engine comprises adjusting the amount of fuel supplied to the identified cylinder.

15. The method of claim 9 , wherein the engine shutdown is an idle engine shutdown performed automatically based on operator requested torque.

16. The method of claim 9 , wherein positioning the engine to the selected engine position comprises adjusting a load placed on the engine during the engine shutdown.

17. A method for an engine having a plurality of cylinders, comprising:
when a fuel system leak test indicates a fuel injector leak, identifying a cylinder of the plurality of cylinders having the fuel injector leak, and at or after engine shutdown, rotating the engine with an electric motor to a selected engine position based on the identified cylinder; and
when the fuel system leak test indicates no fuel injector leaks, at or after engine shutdown, maintaining the engine at a final resting position.

18. The method of claim 17 , wherein the selected engine position is an engine position where the identified cylinder is in an exhaust stroke.

19. The method of claim 17 , wherein the selected engine position is an engine position where an exhaust valve of the identified cylinder is within a threshold range of a position of maximum valve lift for the exhaust valve.

20. The method of claim 17 , wherein when the fuel system leak test indicates no fuel injector leaks, at or after engine shutdown, maintaining the engine at the final resting position comprises maintaining the engine at an undefined final resting position without rotating the engine with the electric motor.

Assignees

• Ford Global Tech Llc

Inventors

• Dudar Aed M

Classifications

• F02D13/08 Primary

  for rendering engine inoperative or idling · CPC title

• F02D41/0295

  Control according to the amount of oxygen that is stored on the exhaust gas treating apparatus · CPC title

• F02N11/0814

  comprising means for controlling automatic idle-start-stop · CPC title

• F02D2041/225

  Leakage detection · CPC title

• F02D41/08

  for idling (F02D41/06, F02D41/16 take precedence) · CPC title