MDUB87

I have a 94 Formula, when I first start the car in the morning you'll barely turn the key over and it'll fire right up. Now after it's ran awhile and you turn it off, and when you go to turn it on again it'll turn over for 15-20 seconds before it starts, it always starts, but takes awhile. It only does this after the engine has been warm, once it's sat over night it starts right up with ease. Any ideas what could be causing this? any insight would be great, thanks!