Method and system for characterizing a port fuel injector

Patent metadata

Field	Value
Publication number	US-10428751-B2
Application number	US-201715492936-A
Country	US
Kind code	B2
Filing date	Apr 20, 2017
Priority date	Apr 20, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

Systems and methods for operating an engine that includes one or more fuel injectors are described. The systems and methods may characterize fuel injector operation during a time when injecting fuel may be useful to maintain balance of a catalyst to reduce engine emissions. Further, large or small amounts of fuel may be injected without affecting engine combustion.

First claim

The invention claimed is:

1. A method for operating an engine, comprising:
increasing pressure of a fuel rail to a threshold pressure and deactivating a cylinder of the engine in response to entering deceleration fuel shut-off;
deactivating a fuel pump in response to pressure in the fuel rail being at the threshold pressure;
injecting fuel to the deactivated cylinder;
correlating pressure drop in the fuel rail to injector operation; and
operating a fuel injector responsive to the correlation.

2. The method of claim 1 , where the fuel injector is a port fuel injector or a direct fuel injector.

3. The method of claim 1 , further comprising closing a throttle of the engine and ceasing spark delivery to the cylinder.

4. The method of claim 1 , further comprising adjusting an amount of fuel injected to the deactivated cylinder responsive to an amount of oxygen stored in a catalyst.

5. The method of claim 1 , further comprising estimating air flow through the engine during deceleration fuel shut-off, and adjusting the air flow through the engine during deceleration fuel shut-off responsive to an amount of oxygen stored in a catalyst.

6. The method of claim 1 , further comprising estimating an amount of oxygen stored in a catalyst during deceleration fuel shut-off.

7. The method of claim 1 , further comprising increasing pressure in the fuel rail in response to exiting deceleration fuel shut-off.

8. A method for operating an engine, comprising:
increasing pressure of a fuel rail to a threshold pressure and deactivating a cylinder of the engine in response to entering deceleration fuel shut-off;
adjusting air flow through the engine during deceleration fuel shut-off responsive to an amount of oxygen stored in a catalyst;
injecting fuel to the deactivated cylinder;
correlating pressure drop in the fuel rail to fuel injector operation; and
operating a fuel injector responsive to the correlation.

9. The method of claim 8 , further comprising adjusting the air flow responsive to a desired amount of fuel injected to the deactivated cylinder.

10. The method of claim 8 , further comprising ceasing spark delivery to the deactivated cylinder.

11. The method of claim 8 , further comprising estimating the amount of oxygen stored in the catalyst during deceleration fuel shut-off.

12. The method of claim 8 , where injecting fuel to the deactivated cylinder includes injecting fuel to the deactivated cylinder a predetermined number of times.

13. The method of claim 8 , further comprising deactivating a fuel pump in response to pressure in the fuel rail being at the threshold pressure.

14. The method of claim 8 , where the correlating includes indicating degradation of the fuel injector when a decrease in pressure in the fuel rail is higher than a threshold.

15. The method of claim 8 , where the correlating includes indicating degradation of the fuel injector when a decrease in pressure in the fuel rail is lower than a threshold.

16. The method of claim 8 , where air flow through the engine is adjusted via adjusting a position of a throttle.

Assignees

• Ford Global Tech Llc

Inventors

• Uhrich Michael James
• Ulrey Joseph Norman
• Pursifull Ross Dykstra

Classifications

• F02P5/1504

  with particular means during a transient phase, e.g. acceleration, deceleration, gear change (during starting F02P5/1506) · CPC title

• F02D2200/0602

  Fuel pressure · CPC title

• F02D2041/3881

  with multiple common rails, e.g. one rail per cylinder bank, or a high pressure rail and a low pressure rail · CPC title

• F02D17/02

  Cutting-out (cutting-out engines in multiple engine arrangements F02D25/04) · CPC title

• F02P9/002

  Control of spark intensity, intensifying, lengthening, suppression (by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12) · CPC title