System and method for deactivating a cylinder of an engine and reactivating the cylinder based on an estimated trapped air mass

1. A system comprising:

a cylinder activation module that:

selectively deactivates and reactivates a cylinder of an engine; and

deactivates the cylinder after intake air is drawn into the cylinder and before fuel is injected into the cylinder or spark is generated in the cylinder, wherein deactivating the cylinder includes closing and disabling an intake valve of the cylinder and an exhaust valve of the cylinder for multiple engine cycles while at least one other cylinder of the engine is active; and

a spark control module that, when the cylinder is reactivated, selectively controls a spark plug to generate spark in the cylinder before the intake valve or the exhaust valve of the cylinder is opened.

2. The system of claim 1 further comprising a fuel control module that, when the cylinder is reactivated, selectively controls a fuel injector to inject fuel into the cylinder before the intake valve or the exhaust valve is opened and before spark is generated in the cylinder.

3. The system of claim 2 wherein the spark control module selectively generates spark in the cylinder before the intake valve or the exhaust valve is opened when a pressure in the cylinder is greater than a first pressure.

4. The system of claim 3 wherein the cylinder activation module estimates the pressure in the cylinder based on a volume, a temperature, and a mass of a charge trapped within the cylinder when the cylinder is deactivated.

5. The system of claim 3 wherein the spark control module generates spark in the cylinder before the intake valve or the exhaust valve is opened when a mass of air within the cylinder is greater than a first mass.

6. The system of claim 5 further comprising a cylinder charge module that estimates a mass of a charge, including the mass of air, trapped within the cylinder when the cylinder is deactivated.

7. The system of claim 6 wherein the cylinder charge module estimates the mass of air trapped within the cylinder when the cylinder is deactivated based on at least one of a manifold pressure, a mass flow rate of intake air, engine speed, a throttle area, and cam phaser positions.

8. The system of claim 6 wherein the cylinder charge module adjusts the estimated mass of the charge based on an amount of flow between the cylinder and a crankcase of the engine as a piston moves within the cylinder when the cylinder is deactivated.

9. The system of claim 8 wherein the cylinder charge module estimates the amount of flow between the cylinder and the crankcase based on a position of the piston and a mass of gas trapped within the crankcase when the cylinder is deactivated.

10. The system of claim 9 further comprising a crankcase gas module that estimates the mass of gas trapped within the crankcase based on at least one of engine speed, an engine coolant temperature, and a pressure in the crankcase.

11. A method comprising:

selectively deactivating and reactivating a cylinder of an engine; and

deactivating the cylinder after intake air is drawn into the cylinder and before fuel is injected into the cylinder or spark is generated in the cylinder, wherein deactivating the cylinder includes closing and disabling an intake valve of the cylinder and an exhaust valve of the cylinder for multiple engine cycles while at least one other cylinder of the engine is active; and

when the cylinder is reactivated, selectively controlling a spark plug to generate spark in the cylinder before the intake valve or the exhaust valve of the cylinder is opened.

12. The method of claim 11 further comprising, when the cylinder is reactivated, selectively controlling a fuel injector to inject fuel into the cylinder before the intake valve or the exhaust valve is opened and before spark is generated in the cylinder.

13. The method of claim 12 further comprising selectively generating spark in the cylinder before the intake valve or the exhaust valve is opened when a pressure in the cylinder is greater than a first pressure.

14. The method of claim 13 further comprising estimating the pressure in the cylinder based on a volume, a temperature, and a mass of a charge trapped within the cylinder when the cylinder is deactivated.

15. The method of claim 13 further comprising generating spark in the cylinder before the intake valve or the exhaust valve is opened when a mass of air within the cylinder is greater than a first mass.

16. The method of claim 15 further comprising estimating a mass of a charge, including the mass of air, trapped within the cylinder when the cylinder is deactivated.

17. The method of claim 16 further comprising estimating the mass of air trapped within the cylinder when the cylinder is deactivated based on at least one of a manifold pressure, a mass flow rate of intake air, engine speed, a throttle area, and cam phaser positions.

18. The method of claim 16 further comprising adjusting the estimated mass of the charge based on an amount of flow between the cylinder and a crankcase of the engine as a piston moves within the cylinder when the cylinder is deactivated.

19. The method of claim 18 further comprising estimating the amount of flow between the cylinder and the crankcase based on a position of the piston and a mass of gas trapped within the crankcase when the cylinder is deactivated.

20. The method of claim 19 further comprising estimating the mass of gas trapped within the crankcase based on at least one of engine speed, an engine coolant temperature, and a pressure in the crankcase.