Ford Global Technolgoies, LLC

Chingpo Liu

Aed M Dudar

Robert Roy Jentz

Imad Hassan Makki

Fling Finn Tseng

Dennis Seung-Man Yang

Russell Randall Pearce

Marcus William Fried

Ron Reichenbach

Methods and systems are provided for detecting leaks in an intake manifold of an engine. In one example, a method may include closing all intake valves of all cylinders of the engine during an engine shut down responsive to vacuum in the intake manifold reaching a pre-determined vacuum level. The method may further include indicating a leak in the intake manifold responsive to a change in a level of vacuum in the intake manifold after closing all the intake valves of all cylinders.

Method for detecting leaks in an intake manifold

A method is provided, comprising terminating a pressure rise portion of an engine-off natural vacuum test based on an initial rate of change of a fuel system pressure upon sealing a fuel system; and initiating a vacuum portion of the engine-off natural vacuum test responsive to suspending the pressure rise portion. The initial rate of change may indicate a likelihood of the pressure rise portion reaching a pressure rise threshold. In this way, the vacuum portion of the test may be initiated earlier, increasing the likelihood of a conclusive result being obtained during a test time limit.

Systems and methods for engine-off natural vacuum leak testing

Methods and systems are provided for improving engine start roughness. In one example, a method for reducing engine start NVH includes operating the engine with a split fuel injection while advancing injection timing as engine coolant temperature increases. The method allows for a smoother engine start while also reducing false misfire incidences.

Method and system for engine cold-start control

A method, comprising indicating an amount of a residual fuel in a fuel tank based on an initial rate of change of a fuel tank pressure during a refueling event. The initial rate of change of fuel tank pressure is proportionate to the amount of vapor dome space within the fuel tank, and thus proportionate to the amount of residual fuel left in the fuel tank. In this way, the fuel tank fill level may be accurately quantified, even during cases where the fill level indicator experiences degradation.

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Novi, MI, United States of America

Chingpo Liu