An inlet fluid booster system for an internal combustion engine having engine cylinders includes a compressed fluid supply source that is in upstream fluid communication with the engine cylinders. A fluid booster is in downstream fluid communication with the compressed fluid supply source for selectively introducing compressed auxiliary fluid from the compressed fluid supply source. The auxiliary fluid is selectively introduced from the fluid booster to have a velocity vector towards the engine cylinders that is greater than a velocity vector away from the engine cylinders.

A method for operating an internal-combustion engine includes increasing a torque demand, controlling a throttle valve, opening an air injection valve and continuously measuring first and second gas pressures with an electronic control unit. The method also includes closing the throttle valve, measuring a first gas mass flow, retarding an ignition angle, and closing the air injection valve. In the method the throttle valve is opened with the control unit when the first gas pressure p.sub.1 equals the second gas pressure p.sub.2. The method also includes continuously controlling the fuel system with the electronic control unit to have a stoichiometric fuel/air ratio of the internal combustion engine being constantly combusting in the internal combustion engine.

A method for operating an internal-combustion engine includes increasing a torque demand, controlling a throttle valve, opening an air injection valve and continuously measuring first and second gas pressures with an electronic control unit. The method also includes closing the throttle valve, measuring a first gas mass flow, retarding an ignition angle, and closing the air injection valve. In the method the throttle valve is opened with the control unit when the first gas pressure p.sub.1 equals the second gas pressure p.sub.2. The method also includes continuously controlling the fuel system with the electronic control unit to have a stoichiometric fuel/air ratio of the internal combustion engine being constantly combusting in the internal combustion engine.

Methods are provided for controlling an engine. One method may include boosting engine intake air to a cylinder; and injecting an amount of a scavenging fluid into the cylinder based on an amount of cylinder residual exhaust gas. A scavenging fluid, such as water or windshield washer fluid evaporates on contact with the hot exhaust gases and hot metal components and the expanded volume of the vapor displaces the residual exhaust gas, thereby improving engine scavenging.

Methods and systems are provided for purging condensate from a charge air cooler towards an intake air filter. In one example, a method may include operating a motor to rotate an engine in reverse and flowing air from the intake manifold to the atmosphere via the charge air cooler to purge condensate towards an intake air filter.

Methods and systems are provided for controlling a condensate level in a charge air cooler. In one example, a method may include adjusting an air flow to a membrane in response to a condensate level in the charge air cooler.