Method for improving spark ignited internal combustion engine acceleration and idling in the presence of poor driveability fuels

A method for accelerating rotational speed of a crankshaft of an internal combustion engine having a plurality of cylinders each having a spark plug wherein a predetermined amount fuel delivered is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the crankshaft based on an acceleration demand made by an operator, the method comprising the steps of:

• receiving the acceleration demand;
• measuring the rotational speed of the crankshaft;
• defining an expected engine speed based on the acceleration demand;
• calculating a speed error as the rotational speed of the crankshaft less the expected engine speed;
• calculating engine acceleration from the rotational speed;
• changing the predetermined amount of fuel delivered to be combusted in each of the plurality of cylinders to reduce the speed error as the speed error changes as a function of the engine acceleration;
• and
• offsetting the firing time of each of the spark plugs to reduce the speed error.

A method for accelerating rotational speed of a crankshaft of an internal combustion engine a plurality of cylinders each having a spark plug wherein a predetermined amount of fuel delivered is to be combusted at a firing time within each of the plurality of cylinders with each rotation of the crankshaft based on an acceleration demand made by an operator, the method comprising the steps of:

• receiving the acceleration demand;
• measuring the rotational speed of the crankshaft;
• defining an expected engine speed based on the acceleration demand;
• calculating a speed error as the rotational speed of the crankshaft less the expected engine speed;
• calculating engine acceleration from the rotational speed;
• changing the predetermined amount of fuel delivered to be combusted in each of the plurality of cylinders to reduce the speed error as the speed error changes as a function of the engine acceleration;
• and
• offsetting the firing time of each of the spark plugs to reduce the speed error;
• calculating a transient fuel scalar as a function of the acceleration demand;
• and
• changing the predetermined amount of fuel delivered to be combusted as a function of the transient fuel scalar.