thanks for comment. I checked the pressure regulator on the fuel rail like you described and no fuel came out. I even turn the key on few time to pressure the system and started the car and nothing came out of the vacuum line on the regulator. As of now i think some how the gas pump over filled the tank and it backup liquid fuel into the evap system and when the pcm told purge valve to open instead of vapor, it flooded the engine cause it to stall. after 4-5 stalls i think the evap was purged of liquid gas.