Power source thermal management and emissions reduction system

A power source may have at least one combustion chamber, a first valve configured to control an airflow between an air source and the at least one combustion chamber and a second valve configured to control an exhaust gas flow between the combustion chamber and an exhaust system. The power source may also have a fuel source configured to supply a fuel to the at least one combustion chamber and a controller operatively connected to the first valve and the second valve. The controller may be configured to determine one or more temperatures and, if the one or more temperatures are below a predetermined threshold, cause the first valve to substantially limit the airflow to the combustion chamber and cause the second valve to substantially limit the exhaust gas flow from the combustion chamber, such that a combustion stroke of one or more combustion cycles is executed with air substantially provided during an intake stroke of a previous combustion cycle.