Just cranking

i have a 1989 honda prelude and when i go out to it in the morning i have to turn the key not to start put just so the lights come on and then it will start. btu after it has ran for a while it gets hot and then when you shut it off for a while it will just crank but if you turn it off and then turn it right back on it will start. and when i put gas in it when i open the gas tank it makes a sound like it is letting air out. please help