89 hard starting?

[doubleR9]

After sitting for a couple of days, and I try and crank it, it will turn over for a while before it cranks then it barely cranks. But if I let off the starter early and hit it again it fires right up. Runs with no problems, no hesitations, no sputtering, no loss of power. Also after I shut it off and try it again it starts no problems. Could it be my filter, if so is it by the fire wall on the passenger side about big as a soft ball? Or could it be the pump and is that in the tank?

It's a 22re Thanks for any help!!