1997 Chevy Monte Carlo wont start

Hello: my 97 z34 is very temper mental right after i fuel the car up,last night after i filled the tank up and when i went to start it ..it did start ,then i put the car in drive ,then it stalled and would not start again,it tried for a few cranks then it was just cranking freely,...i`ve noticed that lately after puting fuel in the car would stall when i would start it but the very next crank it would start right up...and last summer after i drove the car for a short distance and shut the car off then tried to restart it the car wouldnt ..but after a day of sitting it started right up and worked fine untill last night..

any advice would be great
thanks in advance