Method for adapting variations in cylinder-selective injection quantities of a direct injection system and method for cylinder-selectively controlling injection

A method for cylinder-selective injection control in an internal combustion engine with injection system, comprising the following steps:

• a. determining a first adaptation value for adapting a prespecified cylinder-specific fuel quantity to inject into a cylinder in the form of a single quantity in order to achieve a prespecified Lambda value,
• b. determining a second adaptation value for adapting the prespecified cylinder-specific fuel quantity to inject into the cylinder in the form of plural quantities in order to achieve the prespecified Lambda value,
• c. adapting the prespecified cylinder-specific fuel quantity with both the first and second adaptation values, before the fuel quantity is injected in the form of a plurality of fuel quantities,
• d. adapting the prespecified cylinder-specific fuel quantity with the second adaptation value, before the fuel quantity is injected in a lower load and speed range in the form of a single fuel quantity, and
• e. adapting the prespecified cylinder-specific fuel quantity with the first adaptation value, but not the second adaptation value, before the fuel quantity is injected in a range other then the lower load and speed range in the form of a single fuel quantity.

A device for adapting variations in cylinder-selective injection quantities of a direct injection system of an internal combustion engine with a plurality of cylinders, comprising:

• a. means for injecting a prespecified cylinder-specific fuel quantity as a single quantity into the cylinder in accordance with a prespecified Lambda value,
• b. means for determining a cylinder-selective Lambda value resulting from the single quantity injection of the prespecified cylinder-specific fuel quantity,
• c. means for comparing the prespecified Lambda value with the cylinder-selective Lambda value determined from the single quantity injection of the prespecified cylinder-specific fuel quantity,
• d. means for, if the cylinder-selective Lambda value does not match the prespecified Lambda value, determining a first adaptation value for adapting the prespecified cylinder-specific fuel quantity, so that the cylinder-selective Lambda value resulting from the adapted cylinder-specific fuel quantity is synchronized with the prespecified Lambda value,
• e. means for injecting into the cylinder the adapted cylinder-specific fuel quantity in the form of a plurality of fuel quantities and determining a resulting second cylinder-selective Lambda value,
• f. means for comparing the prespecified Lambda value with the second cylinder-selective Lambda value determined from the plural quantity injection of the adapted cylinder-specific fuel quantity, and
• g. means for determining, if the second cylinder-selective Lambda value does not match the prespecified Lambda value, a second adaptation value for further adapting the adapted cylinder-specific fuel quantity, so that the cylinder-selective Lambda value resulting from the further adapted cylinder-specific fuel quantity is synchronized with the prespecified Lambda value.