Method and system for pre-ignition control
AssigneeFord General Technologies, LLC
InventorsChris Paul Glugla, Paul Charles Mingo, Robert Sarow Baskins, Sue Kay Wagers
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for addressing pre-ignition that may be induced in response to actions taken to mitigate a cylinder misfire. An amount of engine load limiting applied may be adjusted to reduce the likelihood pre-ignition while also addressing component over-temperature issues. By limiting an engine load while shutting off fuel in a misfiring cylinder, and while combusting a lean air-fuel mixture in the remaining cylinders, pre-ignition induced by the misfire-mitigating lean combustion conditions can be reduced.
Claims5
A vehicle system, comprising:
- an engine including a plurality of cylinders, each of the plurality of cylinders including a spark plug and a direct fuel injector;
- an intake throttle;
- a turbocharger including an intake compressor driven by an exhaust turbine;
- a knock sensor coupled to an engine block;
- an ionization sensor coupled to each spark plug for estimating an ionization current;
- and
- a control system with code programmed into a computer readable storage medium for:
- indicating a cylinder misfire event based on the ionization current of a spark plug;
- and
- in response to the indication of a cylinder misfire event,
- shutting off fuel to a misfiring cylinder;
- operating remaining cylinders at an air-fuel ratio leaner than stoichiometry;
- and
- reducing an opening of the intake throttle to limit an engine load below a threshold based on a degree of leanness of the air-fuel ratio, and to maintain a turbine inlet temperature below a threshold temperature.
Dependencies are inferred from the claim text.