Strong Fuel Smell From Air Vent Upon Starting Car

1. 1993 Chevrolet Cavalier (4-cylinder)
2. 146,000 miles
3. Automatic Transmission
4. Strong fuel smell comes out of the air vents as soon as I start the car. It goes away after a few minutes and does not come back until I turn the car off and restart it. It doesn't happen every time, either. Probably 6 times out of 10.
5. No fluid leaks are present that I'm aware of.
6. I've had to replace my alternator (smell was present before this), my whole front braking system, my coolant backflow (there was a huge hole in the bottom), front sway bars, and that's all I know about. The transmission hasn't been serviced in years, I imagine. The AC works great (smell is present with that too).

The smell doesn't seem to be coming from the back of the car, near the gas tank, or anywhere you'd expect. It literally blows in through the vents. If I have the vents closed and turned off, I can't smell the gas. (I have a very bad sense of smell. I can't even smell food, so smelling the gasoline coming out of my engine is pretty bad. It's very strong.)

Thank you.