I smell gas upon starting the car in the morning then after 5 minutes it'gone?

What is your question?

3 mechanics tell me different stories of what may be causing the gas smell. Vacume cannister over flowing? Fuel pump problem? fuel injectors clogged? Only smell the gas when starting after the car has been sitting over night parked in the driveway. During the hot climate around 90 degress I don't smell the gas. At 65-70 degrees in the am I smell the gas but no signs of a gas leak. 145,000 miles on car.