Method to perform rebreathe mode transitions

An engine, comprising:

• a plurality of pistons configured to be actuated by combustion reactions within the engine, where the combustion reactions create exhaust gases;
• a crankshaft configured to be actuated by the plurality of pistons;
• a plurality of cylinders, each cylinder being configured to house a corresponding piston of the plurality of pistons and form a containment boundary for a corresponding combustion reaction of the combustion reactions;
• an intake manifold configured to supply a gas mixture to the plurality of cylinders;
• a plurality of intake valves that are each configured to form a controlled fluid passageway for passing the gas mixture from the intake manifold to a corresponding cylinder of the plurality of cylinders;
• a fuel rail connected to a plurality of fuel injectors that are each configured to inject fuel into a corresponding cylinder of the plurality of cylinders, where the injected fuel is combined with the gas mixture to form a fuel mixture that is combusted in the corresponding cylinder during the combustion reaction;
• an exhaust manifold configured to receive the exhaust gases from each cylinder of the plurality of cylinders and combine the exhaust gases into an exhaust stream;
• a plurality of exhaust valves that are each configured to form a controlled fluid passageway for passing the exhaust gases from a corresponding cylinder of the plurality of cylinders to the exhaust manifold;
• an Electronic Control Unit (ECU) configured to coordinate operations of the intake valves, the exhaust valves, and the fuel injectors based upon a position of the crankshaft in such a manner that the ECU controls the engine to operate in at least two modes including a typical engine operating mode and a rebreathe engine operating mode,
• wherein the typical engine operating mode comprises the ECU controlling the exhaust valves to be actuated after the intake valves are actuated, and the rebreathe engine operating mode comprises the ECU controlling the exhaust valves to be actuated both during and after the intake valves are actuated, and
• wherein the ECU is configured to control a Start of Injection (SOI) of the fuel injectors to be retarded during the typical engine operating mode, relative to the SOI of the fuel injectors during the rebreathe engine operating mode, and
• wherein the ECU controls the SOI of the fuel injectors to be advanced during the rebreathe engine operating mode, relative to the SOI of the fuel injectors during the typical engine operating mode.