94 dakota idle problemd

I have a 94 dakota with a 5.2 ,when it's cold
it starts up and runs like a new truck for
about eight to ten minutes,and then it runs
terrible,missing,and dies a couple times ,and
you can smell raw gas,it does this for about
ten minutes,and then it runs good again,it
runs fine all day long but every time it gets
cold it goes through the same thing