BAD 24/7

Greetings,

I'm new to the forum. Happy to be here. I've been trying to find solutions to my problems, but have been unsuccessful.

I currently am trying to maintain my new to me 1995 Nissan 300ZX 2+0 NA, here is what I have been experiencing:

Usually when I fill my car past 3/4 tank, and after driving about 30 minutes the car would start to fun rough, like it is getting too much fuel or not enough air and the RPMS will drop until it stalls. Each time that this happens, I would find a steady leak of gas coming from the front left (driver side) of the vehicle.
-There is a port below the carbon canister that returns to the fuel system and a port that is open for air (based on my research it should be open and plugging it would only cause engine to stall more frequently).
-Purging the gas cap usually stops the flow of gas if it has begun to spill out the front.
-This only happens when car has 3/4 tank of gas or more or on hot days.

I believe that so much pressure builds up in the tank that it takes the path of least resistance and flows out of the port below the carbon canister. However, there could be plenty of parts/problems that it could be and I would like to get this problem fixed before the others. I'm the 10th or so owner to the car and do not know what has been done to it by some lousy owner or mechanic.

If anybody has experienced the same or has any suggestions, please chime in.

Cheers! TIA!