1994 GMC C1500 engine stalls

Engine Performance problem
1994 GMC C1500 6 cyl Two Wheel Drive Automatic

when starting engine if it doesnt start at the first click, you have to hold accelerator to the floor til it starts. Then alot of black smoke comes out of exhaust. Once started I either go 1 mile or 5 miles and it acts like im running out of gas.. Then eventually will start again. And then do the same.