Engine de-choking in response to an engine flood event

• US 9,347,390 B2
• Filed: 03/20/2013
• Issued: 05/24/2016
• Est. Priority Date: 03/20/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Glugla, Chris Paul, Czekala, Michael Damian, Shelby, Michael Howard
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): JIN, GEORGE C.
• Application Number:
  US13/847,593
• Publication Number:
  US 20140288808A1
• Time in Patent Office: 1,161 Days
• Field of Search: 123/179.18, 123/179.16, 123/198.DB, 123/491, 123/16, 701/102
• US Class Current: 1/1
• CPC Class Codes: F02D 2009/0205 working on the throttle valve and another valve, e.g. choke
• CPC Class Codes: F02D 2009/025 Opening the throttle a little during starting
• CPC Class Codes: F02D 33/006 depending on engine operating conditions, e.g. start, stop or ambient conditions
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02D 41/067 with control of the choke non electronic control of choke see F02M1/10
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 11/0848 with means for detecting successful engine start, e.g. to stop starter actuation
• CPC Class Codes: F02N 2019/002 Aiding engine start by acting on fuel
• CPC Class Codes: F02N 2200/02 said parameters being related to the engine
• CPC Class Codes: F02N 2250/06 Engine stall and related control features, e.g. for automatic restart
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y10S 903/905 Combustion engine

Abstract

A method may comprise automatically de-choking an engine and cranking the engine in response to an engine flood event, wherein automatically de-choking the engine comprises automatically cutting fuel to the engine while opening an air intake throttle.

Claims

1. A method, comprising:

automatically de-choking a non-carbureted engine, including automatically cutting fuel to the engine while increasing an air intake throttle opening, and cranking the engine in response to detecting an engine flood event, the engine flood event detected based on an amount of fuel delivered to the engine during engine start attempts.

2. The method of claim 1, wherein detecting an engine flood event further comprises detecting an engine stall.

3. The method of claim 2, wherein de-choking the engine further comprises adjusting an air-fuel ratio to a de-choking air-fuel ratio.

4. The method of claim 2, wherein de-choking the engine further comprises extending a cranking duration to increase purging of fuel from the engine.

5. The method of claim 1, further comprising detecting the engine flood event based on a number of engine start attempts being greater than a threshold number of engine start attempts.

6. The method of claim 1, further comprising detecting the engine flood event based on a cranking duration being greater than a threshold cranking duration.

7. The method of claim 1, further comprising detecting the engine flood event based on an elapsed time since a last engine start attempt being less than a first threshold time.

8. The method of claim 1, further comprising detecting the engine flood event based on an elapsed engine-on time being less than a second threshold time, where elapsed engine-on time indicates an engine-on time until the engine is turned off.

9. A method of automatically de-choking an engine, comprising:

cutting fuel to engine fuel injectors;

increasing an opening of an intake air throttle;

cranking the engine for an extended cranking duration; and

adjusting an air-fuel ratio to a de-choking air-fuel ratio, wherein automatically de-choking the engine is performed in response to detecting an engine flood event including detecting an engine stall event.

10. The method of claim 9, wherein the engine stall event is detected based on an abrupt ceasing of engine operation when a transmission is not engaged in park or neutral.

11. The method of claim 9, wherein detecting the engine flood event further comprises detecting a crank duration exceeding a threshold crank duration and/or a number of engine start attempts exceeding a threshold number of engine start attempts.

12. The method of claim 9, wherein detecting the engine flood event comprises detecting an elapsed time since a last engine start attempt exceeding a first threshold time and/or an elapsed engine running time less than a second threshold time.

13. A method of automatically de-choking an engine, comprising:

in response to an engine flooding event based on a total amount of fuel delivered during a start being greater than a threshold;

cutting fuel to engine fuel injectors;

increasing an opening of an intake air throttle;

cranking the engine for a first extended cranking duration; and

adjusting an air-fuel ratio to a de-choking lean air-fuel ratio; and

in response to an engine stall event based on an abrupt ceasing of engine operation when a transmission is not engaged in park or neutral;

cutting fuel to engine fuel injectors;

increasing the opening of the intake air throttle;

cranking the engine for a second extended cranking duration longer than the first extended cranking duration; and

adjusting the air-fuel ratio,

wherein automatically de-choking the engine is performed in response to detecting the engine flood event.

14. The method of claim 13, wherein the engine is part of a hybrid system and the engine comprises a non-carbureted engine.