2001 Mercury Villager Hard starting when warm

Thank you for your answer,

In a cold morning the van starts just fine, but once the car is warmed up it takes about
2 tries to start the van. During the stating process it is a bit erratic, but then settles down.
In idle the car is a bit unstable. I have replaced the spark plugs, spark plug-wires, cap & rotor, and the started was replaced this summer. Any feedback would be appreciated. Thank you.