hold pedal to floor to start

99 ford contour 2.0 have to hold pedal to floor to start when cold to warm, starts fine when at operating temp. hold pedal to floor it starts then you have to back off pedal to three quarters to keep it running then it runs rough till it clears out and black smoke comes out tail pipe then it runs fine when its hot it starts right up some times it starts right up when cold but not when warm