	US 7,607,410 B2
	System and method of controlling fuel delivery during positive valve overlap operation of an engine start
Steve Magner, Farmington Hills, Mich. (US); Xiaoying Zhang, Dearborn Heights, Mich. (US); John Rollinger, Sterling Heights, Mich. (US); Mrdjan Jankovic, Birmingham, Mich. (US); and Sue Wagers, Newport, Mich. (US)
Assigned to Ford Global Technologies, LLC, Dearborn, Mich. (US)
Filed on Jun. 12, 2006, as Appl. No. 11/423,682.
Prior Publication US 2007/0283933 A1, Dec. 13, 2007
Int. Cl. F01L 1/34 (2006.01)

U.S. Cl. 123—90.15 [123/348; 123/491]

15 Claims

1. A method for controlling fuel injection into an engine of a vehicle, the engine having at least a variable intake valve timing system, the method comprising:

cold starting the engine with the variable valve timing system at a default position;

before the engine warms to a warm-up temperature, adjusting the variable intake valve timing system to generate an increase in positive valve overlap of at least one cylinder;

adjusting a fuel injection amount in response to said increase in positive valve overlap, where said adjusting the fuel injection amount provides a decrease in injected fuel to account for an increase in fuel evaporating from the intake valve and/or the intake port as engine temperature warms; and

adjusting spark timing in response to said adjusting of the variable intake valve timing system and further to maintain engine idle speed.