An aircraft propulsor comprising: an internal combustion engine comprising an intake, a combustion chamber coupled to the intake, and an exhaust coupled to the combustion chamber; a turbocharger coupled to the exhaust and configured to be powered by flow within the exhaust; an injector coupled to the exhaust, disposed between the combustion chamber and the turbocharger, and configured to deliver fuel to a portion of the exhaust; an igniter coupled to the exhaust, disposed between the combustion chamber and the turbocharger, and configured to ignite the fuel delivered by the injector to the portion of the exhaust; one or more sensors to determine if the internal combustion engine has shut down during powering an aircraft; a controller configured to carry out the following steps: determining that the internal combustion engine has shut down during powering an aircraft; flowing, responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering, with the injector, the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter; and spooling, responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor. an internal combustion engine comprising an intake, a combustion chamber coupled to the intake, and an exhaust coupled to the combustion chamber; a turbocharger coupled to the exhaust and configured to be powered by flow within the exhaust; an injector coupled to the exhaust, disposed between the combustion chamber and the turbocharger, and configured to deliver fuel to a portion of the exhaust; an igniter coupled to the exhaust, disposed between the combustion chamber and the turbocharger, and configured to ignite the fuel delivered by the injector to the portion of the exhaust; one or more sensors to determine if the internal combustion engine has shut down during powering an aircraft; a controller configured to carry out the following steps: determining that the internal combustion engine has shut down during powering an aircraft; flowing, responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering, with the injector, the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter; and spooling, responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor. determining that the internal combustion engine has shut down during powering an aircraft; flowing, responsive to the determining that the internal combustion engine has shut down, air through the internal combustion engine to the exhaust by electrically motoring or windmilling the engine; delivering, with the injector, the fuel to the portion of the exhaust upstream of the turbocharger to create a mixture with the fuel and the air; igniting the mixture with the igniter; and spooling, responsive to the igniting the mixture, the turbocharger for easier restarting of the aircraft propulsor.