Patent ID: 7370629

Claim:
A method for operating a spark-ignition internal combustion engine ( 10 ) including a combustion chamber ( 18 ) with a fuel injector ( 20 ) for direct fuel injection into a combustion chamber ( 18 ) and a spark plug ( 26 ) for the ignition of the fuel with combustion air supplied to the combustion chamber ( 18 ) in a post-start phase (T) during a period between the start-up phase of the internal combustion engine and before the lambda sensors is operational, wherein the engine is operating at low temperatures, said method comprising the steps of: Supplying the combustion air to the combustion chamber ( 18 ) in an engine intake stroke; injecting a pilot fuel quantity by means of the fuel injector ( 20 ) into the combustion air supplied to the combustion chamber ( 18 ) during the intake stroke of the internal combustion engine ( 10 ), said pilot injection (M H ) forming a homogeneous, lean air/fuel mixture (λ<1) in substantially the entire combustion chamber ( 18 ); subsequently injecting in a main injection (M S ) a second fuel quantity into the combustion chamber ( 18 ) during a compression stroke directly before the ignition time (ZT), said main fuel injection (M S ) being carried out as a double injection each forming a stratified, rich air/fuel mixture (λ<1) in the region of the spark plug ( 26 ) and igniting the stratified rich air/fuel mixture by means of the spark plug ( 26 ) at a predetermined ignition time (ZT) after the second stratified fuel injection.