Hyundai Repair: Santa Fe hard start after fill up, fuel vapors, excess fuel

Question
Hi ;
Ii have strange problem. My Santa fe works fine. However, everytime I fill up, it does not want to start. It cranks and I have to give it some gas and it will idle rough. After about 30s or so, it will stay running somewhat rough with my foot off the gas. After that all is well. All subsequent starts are smoothe until I fill up again.
No Check Engine light; No codes. Thanks for your help.

In addition, if the car is running and I remove the gas cap, it stalls and shuts off.

I had lost my gas cap a whiles back - I replaced it with a non-dealer one. I don't think this is the issue because it shuts off without a gas cap as well - but I could be wrong.

Answer
Your purge control valve is probably stuck open.  Under normal operation, the ECM (Engine Control Module) opens and closes this valve when you're driving to burn off excess fuel vapors.  If it's stuck open, the a large amount of vapors will be pushed out of the tank and into the engine when you fuel, causing the engine to be flooded.