Car slows down while driving, then all the sudden it speeds up again.

What is your question?

I have an 04 KIA spectra. Once in a while I will be driving around and my foot will be on the gas pedal, then all the sudden my car starts slowing down, even though I still have foot on the gas. Then it just slowly speeds back up again and is fine. Not sure what to do. It doesn't do it everyday, just once in a while. Also, when I put gas in my car, my car doesn't always want to turn over, if I don't put my foot on the gas a little when turning it on, it just shuts off right away. This happens almost everytime. I don't know if these things are connected somehow, but I thought I would share and see if anyone might know what's going on.