I had the same problem with my 88 accord. When I was dorming years ago I would leave the car in the parking structure for a couple of days and when I came back it stank of gas. I'm trying to find the repair bill from that time but it was like 6 years ago so I don't think I'm gonna find it but if I do I'll let you know what I had repaired. If you know you're gonna leave it parked for a while and if it's safe you may want to leave your windows cracked open a little so that the smell won't be so intense.