Passenger window and door will not open nor both back door

if i remove gas cap there is a dramatic change in my car, it wants to quit. when i put gas in it and then replace the cap I have to almost keep my foot on the gas to keep it from dying. and it remains like that for about the first couple miles after putting gas in car. this is the only time the car acts like this.

I changed lights. Fuses all.

Sometimes wnt start unless i give er a lil gas. And its getin were its doin the sputtering everytime but once i get it to going good it stops and gains power again

I just put the motor in an I can tell that it been sitting up for a while..