1996 Pontiac Bonneville starting real hard

I have a 1996 pontiact bonneville and have just replaced the iridium spark plugs and spark plug wires, but it is still starting real hard. It takes 2 to 3 times for it to finally start and and it will run ruff for about 1 to 2 minutes and then it will start to smoth out. While I'mdriving it right after it starts does not seem to have the pick-up it use to have. If you have any ideas I would really appecciate to no end thank you very much. Mark B in Toledo Ohio