Back to results
US 2016/0258375 A1Published application
Method and system for determining air-fuel ratio imbalance
AssigneeFord Global Technologies, LLC
InventorsHassene Jammoussi, Imad Hassan Makki, Michael I. Kluzner, Robert Roy Jentz
Life of this patent
Estimating the term…
Abstract
Methods and systems are presented for assessing the presence or absence of cylinder air-fuel ratio deviation that may result in air-fuel ratio imbalance between engine cylinders. In one example, the method may include assessing the presence or absence of air-fuel ratio errors based on deviation from an expected air-fuel ratio during a deceleration fuel shut-off event.
Claims20
A method, comprising:
- during a deceleration fuel shut-off (DFSO) event, sequentially firing cylinders of a cylinder group, each fueled with a selected fuel pulse width, and
- indicating an air-fuel ratio variation for each cylinder based on air-fuel deviation from a maximum lean air-fuel ratio during the DFSO.
A method, comprising:
- after disablement all cylinders leading to a common exhaust of an engine:
- individually fueling one or more of the disabled cylinders to combust a lean air-fuel mixture;
- and
- adjusting engine operation in response to a perturbation in exhaust air-fuel ratio from a maximum lean air-fuel ratio.
1 more element
A method, comprising:
- after disablement all cylinders leading to a common exhaust of an engine:
- individually fueling one or more of the disabled cylinders to combust a lean air-fuel mixture;
- and
- adjusting engine operation in response to an exhaust air-fuel ratio deviation from an expected engine air-fuel ratio, the exhaust air-fuel ratio deviation occurring when all cylinders except a cylinder receiving fuel are deactivated.
1 more element
Dependencies are inferred from the claim text.