964 will not start after fuel fill-up

[JJAYALA]

Hello everyone,
I am having a problem that I hope is simple but could use help. I have a 1991 Porsche 911 C4 which was running fine until I went to the gas station the other day to fill up the gas. The car had been sitting in garage for about 3 months prior to that. It started fine and mu first trip was to the gas station.
After the fill-up the car tries to start but engine shakes violently and turns off. I tried starting the car with the gas pedal all the way down and it works and can be driven but it stalls if I come to a stop.
I also noticed that it starts and runs better if I take of the gas cap. This seems to be pointing to the Gas Bleeder Valve but wanted to check if others have had this issue and found a solution.
Thanks