US 8,408,176 B2 · System and method for reducing hydrocarbon emissions in a gasoline direct injection engine

Abstract

A method is described for starting an engine of a motor vehicle under varying temperature conditions. The method may include during a first, higher-temperature, starting condition, directly injecting fuel into all of the combustion chambers the initial fueled cycle comprising crankshaft rotations during which at least some fuel is injected for a first time since the engine was brought from rest. Further, during a second, lower-temperature, starting condition, the method includes directly injecting fuel into less than all of the combustion chambers during at least the initial fueled cycle of the engine. In this way, it is possible to prevent the engine's pump from being outstripped during cold-start conditions at low engine temperatures. Also, it may allow subsequently fueled cylinders to start at a higher engine speed and lower manifold air pressure than otherwise possible, thereby further reducing the need for overfueling.

Claims20

Dependent claims

A method for starting an engine of a motor vehicle under varying temperature conditions, the engine having a plurality of combustion chambers and a pump for pressurizing fuel for delivery to the combustion chambers, the method comprising:

during a first, higher-temperature, starting condition, directly injecting fuel into all of the combustion chambers during at least an initial fueled cycle of the engine, and spark igniting the fuel to increase a rotation speed of the engine, the initial fueled cycle comprising two rotations of a crankshaft of the engine during which at least some fuel is injected for a first time since the engine was brought from rest;
and
during a second, lower-temperature, starting condition, directly injecting fuel into less than all of the combustion chambers during at least the initial fueled cycle of the engine, and spark igniting the fuel to increase the rotation speed of the engine, wherein a throughput capacity of the pump would be exceeded during the initial fueled cycle if the fuel were directly injected into all of the combustion chambers in the amounts directly injected into the less than all of the combustion chambers during the second starting condition.

A system for starting an engine of a motor vehicle, the engine having two or more combustion chambers, the system comprising:

a first plurality of fuel injectors directly coupled to the two or more combustion chambers, the first plurality of fuel injectors including a second, lesser, plurality of fuel injectors;
a pump configured to provide fuel to the first plurality of fuel injectors, a throughput capacity of the pump being greater than a desired rate of fuel delivery to the first plurality of fuel injectors during a first starting condition of the engine, and less than the desired rate of fuel delivery to the first plurality of fuel injectors during a second starting condition of the engine;
and
a controller operatively coupled to the first plurality of fuel injectors, the controller configured to enable fuel injection via the first plurality of fuel injectors during the first starting condition and via the second plurality of fuel injectors during the second starting condition;
and
a memory module embodying a record of start-up misfire for the two or more combustion chambers, wherein the controller is further configured to disable fuel injection from at least one fuel injector during the second starting condition based on the record of start-up misfire.

3 more elements

Dependencies are inferred from the claim text.

System and method for reducing hydrocarbon emissions in a gasoline direct injection engine

Life of this patent

System and method for reducing hydrocarbon emissions in a gasoline direct injection engine

Life of this patent

Abstract

Claims20