fuel odor in cabin after sitting closed up

porscheme2 · 04-20-2005, 03:03 AM

Completely rebuilt a 1976 911s, everything. All fuel/vapor hoses replaced, etc. Picked up the car in pieces, had the dashboard out, and never saw little plastic gas box or hose under the dash. Did this model year have that box? Any help would be appreciated.

svandamme · svandamme's Garage

leaking tank?
i had the exact same thing when i got mine

didn't find the source at first, because the bottom of the tank, is covered in coating from the factory

and the seam of the tank is resting on a seal...

the leak became very apparant, after i drove it on a gras parking, and the semi long grass , wetted the undercoating , and took off the bad parts... drove off, didn't smell thing while driving topless, but suddenly ran out of fuel .... reserve came on, and car stalled a mile later... not even enough time to find fuel station

IROC · IROC's Garage

One other simple thing to check is the gas cap. The seal on it wears out over time and will allow fuel vapors to escape. Happened to me once...

Mike

porscheme2 · 04-20-2005, 03:26 AM

Had the tank out, flushed, replaced gas cap.

SeattleDriver · 04-20-2005, 09:34 AM

I posted the same question a few days ago and received a lot of very good advice. Here is a link to that post:

Gas Smell

I eventually found the source, but it was completely different from the suggestions. Earlier I had taken off the muffler and put on short pipes to see how it would run with a different exhaust system. That's when I started to have a gas smell. When I put the original muffler back on, the smell went away! I don't know much about engines, or why, but it worked! I would think that a gas smell coming out of my exhaust system would cause a lot of backfires, but it doesn't.

targa911S · 04-20-2005, 09:56 AM

Also try the gasket under the sending unit for the gas gauge. It dries out and shrinks. The gas box, that I know of, is not repairable. It is made from a poly carb that nothing will stick to. Some guys have had success with heat "welding" it.

scedmonds · scedmonds's Garage

Isn't the gas/oil smell in a Porsche cabin a FEATURE?

Cheers!

C.

targa911S · 04-20-2005, 12:04 PM

LOL!! that's true

porscheme2 · 04-20-2005, 02:36 PM

I don't mind the odor, but I'm a little confused. I've replaced all the pressure, return, vacum, and fuel vapor lines. The fuel pump, accumulator, WUR all replaced. Had the car completely stripped, interior and exterior, and flushed/checked the fuel tank. I worked 2 1/2 yrs on this vehicle, and I would like to get to the bottom of this. I have not seen any lines that may or may not have gone to the mysterious black box under the dash, nor have I seen a box.