1988 Dodge Ram im going crazy here help me figure this out

i have a 1988 dodge ram d150 with a 318 i just bought this car off of a farmer and it has been sitting for a year i got every thing checked out and it acts funny when you start it up some times it idles good and some times it idles ruff if you take off fast it goes good but if you take off slow it runs crappy like it is out of gas what would it be????