Gasoline smell inside car - except when cold

I have an annoying problem with my 1998 3.8L Lumina LTZ. I have a strong fuel smell inside when I start the car again after it has been driven and parked. I never smell gas when I start it cold, only when recently driven (warm). I can't see any fuel leaks at all. Any ideas? Why would it smell inside and not outside? There are no internal wet spots or other evidence

Got the same car, fun, bit of a sleeper for a Lumina, anyway, pull the vaccum hose off the fuel press. regulator see if it is wet inside. Look for leaks around the fuel filter and fuel tank seams also.

Take the decorative (NOT) cover off the engine and look at the quick-connect that supplies the fuel rail. Mine was leaking at 80K miles on my 98 LTZ. The Orings inside the connector were dryed out and cracked. GM does not sell just the orings(nor could I find them at parts stores). Gm will sell a complete fuel line for $65, But I fixed mine with $1.50 worth of high pressure fuel line and a pair of screw clamps. Not sure if this is the same problem you had, but worth looking at.

IF no leak is present in the engine bay, I would look at the fuel tank purge valve. It regulates pressure in the fuel tank, which increases the longer the car runs due to fuel returning to the tank and air displacement. When they stick, it will cause fuel smell in the cabin.

Check the fuel pressure regulator. I had the same problem and it turned out that the vacuum diaphram in the regulator degraded to the point that when the engine was running it would suck gas into the intake manifold. Here's some clues: 1) Immediately after you turn off the engine you may smell gas in the throttle body 2) Fuel rail doesn't hold pressure right after you turn off the engine 3) Disconnect the vaccum line going to the regulator and check if gas seeps out of the line. 4) Idle fluctuate up and down and stalls, then hard to start. Good luck.