Odd fuel odor? Can anybody help me identify where its coming from?

[modmonster2008]

So a couple months ago i did a head gasket change on my Supra, did the typical runthough of the vacuum hoses and EGR stuff to make sure nothing was not installed, and i also got the new crush washers for the fuel banjo bolt that goes on the rail, no leaking fuel anywhere, but once in a while i would smell a strong fuel odor coming from somewhere underneath the car around the engine bay area, though there are no smells in the engine compartment itself, i smell it standing 3-4 feet away from the car, can anybody chime in on this one? Anything would be appreciated, thanks!

 

[RazoE]

is your charcoal canister hooked up correctly.?

 

[modmonster2008]

EDIT: Charcoal canister seems to be installed correctly no hoses that are loose, fuel rail area has no gas odor, it seems to be coming from under the car around the door/ fender area but no leaks are present, im stumped

 

[jetjock]

If you can smell raw fuel there's a leak. Jumper the fuel pump on and inspect the system paying particular attention to the supply and return lines. An emissions analyzer makes that easy but I'm guessing you'll have to do it the old fashioned way...

 

[modmonster2008]

Jetjock - if there was a leak in the fuel system wouldnt that mean i would smell the fuel odor almost always (most of the time) ? I only do stumble across the odor once in a while, regardless of my driving patterns and whatnot

 

[Poodles]

Motor will move opening and closing the leak. Check the soft lines especially.

 

[modmonster2008]

Will do a thorough check hopefully on saturday or so after the schedule gets freed up. Hopefully its just a cracked softline or a loose clamp, id rather not deal with anything serious right now

 

[jetjock]

What Poodles said. Even if the smell is coming from something else the fuel system is still the most logical place to begin looking. A rest pressure check might also help but the leak may either not be present during that time or be too small to effect rest pressure. You could also crank up the pressure to help find it...

 

[modmonster2008]

weird how the odor comes from underneath the car at least from what i smell, no scent from the engine bay, nor at the fuel cap area or the fuel tank..

 

[modmonster2008]

Well, lesson learned. NEVER get an Autozone cap, figured it was the one as when i usually fill up the tank for gas, the cap would hiss when i remove it, but no it doesnt, i opened the fuel door when the strong smell was occuring, sure enough after replacing with a OEM cap, hiss was back and the fuel odor was gone!

 

[hvyman]

What about a bad charcoal canister thats dumping fuel?


Fuel vapors pretty quick so it could be in a hard spot. Bust out the super flashlight with a mirror and start looking really close. Dont double triple guess find out for sure.

 

[modmonster2008]

Well, i checked the charcoal canister it wasnt coming from that area at all, and pretty much when the car is shut off it comes from the fuel door area, and was verified when i opened the gas door it was the area with the strongest smell, been almost a week when i got a new OEM gas cap, and i havent noticed the smell yet,

 

[OneJArpus]

Change the gas cap, see if that changes the smell for you in that area, i had a similar issue and it was my gas cap.

 

[Skeezix]

I've noticed a hiss when I take off my gas cap only when it's really low on gas. Not on my supra but previous cars. The cap I have now is locking and where you put the key in you can push down to vent it before unscrewing to prevent the hissing. Anyone see or use these before?

 

[modmonster2008]

^ Lol my car is always low on gas haha, but i believe i have not seen a locking push vent gas cap, ive seen one or the other, but not at the same time.