Abstract: Methods and systems are provided for addressing pre-ignition occurring while operating with blow-though air delivery. A variable cam timing device used to provide positive intake to exhaust valve overlap is adjusted in response to an indication of pre-ignition to transiently reduce valve overlap. Pre-ignition mitigating load limiting and enrichment applied during a blow-through mode is adjusted differently from those applied when blow-through air is not being delivered.

Abstract: Methods and systems are provided for addressing pre-ignition occurring while operating with blow-though air delivery. A variable cam timing device used to provide positive intake to exhaust valve overlap is adjusted in response to an indication of pre-ignition to transiently reduce valve overlap. Pre-ignition mitigating load limiting and enrichment applied during a blow-through mode is adjusted differently from those applied when blow-through air is not being delivered.

Abstract: Methods and systems are provided for addressing pre-ignition occurring while operating with blow-though air delivery. A variable cam timing device used to provide positive intake to exhaust valve overlap is adjusted in response to an indication of pre-ignition to transiently reduce valve overlap. Pre-ignition mitigating load limiting and enrichment applied during a blow-through mode is adjusted differently from those applied when blow-through air is not being delivered.

Abstract: Methods and systems are provided for addressing pre-ignition occurring while operating with blow-though air delivery. A variable cam timing device used to provide positive intake to exhaust valve overlap is adjusted in response to an indication of pre-ignition to transiently reduce valve overlap. Pre-ignition mitigating load limiting and enrichment applied during a blow-through mode is adjusted differently from those applied when blow-through air is not being delivered.

Abstract: This invention relates to an apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter. Provided is an open loop fuel controller comprising a detector arranged down stream of a catalyst for detecting rich breakthrough; a catalyst model having an estimator for estimating a stored oxygen level in the catalyst; a comparator for comparing an estimated stored oxygen level with a plurality of predetermined thresholds; demand adjusting means for adjusting an air fuel ratio demand in dependence upon a received signal from said comparator and upon a received signal from said detector. A method of open loop fuel control is also provided.

Abstract: This invention relates to an apparatus for controlling the air-fuel ratio demanded by a fuel controller in order to maintain optimum performance of a catalytic converter. Provided is an open loop fuel controller comprising a detector arranged down stream of a catalyst for detecting rich breakthrough; a catalyst model having an estimator for estimating a stored oxygen level in the catalyst; a comparator for comparing an estimated stored oxygen level with a plurality of predetermined thresholds; demand adjusting means for adjusting an air fuel ratio demand in dependence upon a received signal from said comparator and upon a received signal from said detector. A method of open loop fuel control is also provided.