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Rezarf
07-21-2013, 10:43 PM
Hey guys and gals...

My 1995 Corolla is stinking of gas when I get out of it after some driving. I have seen no drop in power or mileage... its hard to tell where the gas smell is coming from. I don't see any obvious leaks, there is no sign of anything leaking/dripping. But the fuel smell is really strong after a little driving.

Thoughts on what to start checking?

loudbay
07-22-2013, 12:44 AM
Charcoal canister / egr recirculating valve....

DaveInDenver
07-22-2013, 07:14 AM
Charcoal canister / egr recirculating valve....
These would be my first check, too.

Rzeppa
07-22-2013, 10:21 PM
It wishes it were an FJ40 ;-)

AxleIke
07-23-2013, 11:53 AM
Yup. Charcoal canister. In addition, check to be sure your exhaust hasn't pushed up too near the tank (shouldn't be close as I think its on the opposite side of the car). The heat from the exhaust will heat the tank and cause excess pressure which will push gas out of the canister too. Had this happen once.

Rezarf
07-23-2013, 06:10 PM
Charcoal canister / egr recirculating valve....

Sweet, thanks I'll look there first.

It wishes it were an FJ40 ;-)

My 40 always stinks of gas:hill: I think I have a normal 40, but on the corolla the it's just weird!

Yup. Charcoal canister. In addition, check to be sure your exhaust hasn't pushed up too near the tank (shouldn't be close as I think its on the opposite side of the car). The heat from the exhaust will heat the tank and cause excess pressure which will push gas out of the canister too. Had this happen once.

The exhaust runs on the other side of the tank, but I will look and make sure it hasn't got knocked around. Thanks Isaac.

RockyMtRunner
07-28-2013, 09:05 AM
Yep, the canister most likely. I damaged the one in my 3rd Gen 4Runner by over-filling the fuel tank and then tipping the rig every which way while wheeling. The charcoal becomes saturated and ruined. What you are smelling is probably fumes from the feedback system, not dripping gas. Hot weather makes it smell worse. I had to replace the canister; then good again. When the gas pump clicks off the first time, stop filling. Only my opinion, for it's worth.

PabloCruise
07-29-2013, 06:24 AM
So the charcoal cans do go bad?
There is a difference in smell between raw gas, and gas vapors from the charcoal canister.
My wife's Camry has a gassy smell, but it smells like gas vapor from the can. I checked all the lines to and from the can, and they look intact, so it left me scratching my head...

DaveInDenver
07-29-2013, 07:30 AM
Charcoal filters can sorta go bad, they have two or three check valves that control the flow. The concept is to absorb excess gas and return it to the tank or as vapor back into the combustion process when possible. They store the fuel with activated carbon, which provides a lot of surface area in a small volume. If you continually saturate the carbon that also ruins it eventually.

Diagnosis is to put low pressure on the tank port and listen for the check valve to click open and close when you remove the pressure. It should be a distinct click. You then put low pressure on the purge port (the one to the throttle body) and should get no flow from either the tank or atmospheric ports. If it fails either of these test the book says to replace it.

But, you can clean them sometimes by using the purge process. My '91 FSM says to purge a saturated can you use 43 psi of air pressure on the pipe that goes to the tank, plugging the purge pipe to the throttle body and allowing air to flow from the atmospheric port on the bottom (this is normally where the smell comes from).

Apparently if you're careful you can spray carb cleaner into the tank and purge ports to de-gum the the check valves. Never tried this, so don't know if it works or not.

http://www.autoshop101.com/forms/h62.pdf

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2367070

PabloCruise
07-29-2013, 12:02 PM
Thanks Dave.
In my unique way of thinking, I wonder about creating a vacuum on the purge port to pull fresh air through from the atmospheric opening on the bottom (that sounds weird) through the charcoal.
I am very hesitant to use a shop vac to pull gasoline vapors, as that sounds like I could end up winning the Darwin awards, plus, I think it could end up being too much vacuum on the media inside the can.
Is there a tool that would use compressed air source to generate a smaller vaccum? I would think that could be useful, especially if you could use it to suck up old nasty brake fluid in brake and clutch master cylinders prior to changing out fluid.

DaveInDenver
07-29-2013, 12:14 PM
I use a turkey baster to suck up the fluid from the master cylinders before working on the brakes or clutch. Doesn't have to be sophisticated. :-)

Yeah, using a shop vac does not instill confidence and the education stuff I linked to (autoshop101) has some sort of tool that uses nitrogen when working on these things because they say introducing compressed air into a fuel is dangerous. I'm not sure why the older manuals talk about shop air purges but I guess in concept hooking 43 psi to a saturated fuel canister is a bit like a supercharged engine waiting for a spark.

PabloCruise
07-30-2013, 05:03 PM
I use a turkey baster to suck up the fluid from the master cylinders before working on the brakes or clutch. Doesn't have to be sophisticated. :-)

Yeah, using a shop vac does not instill confidence and the education stuff I linked to (autoshop101) has some sort of tool that uses nitrogen when working on these things because they say introducing compressed air into a fuel is dangerous. I'm not sure why the older manuals talk about shop air purges but I guess in concept hooking 43 psi to a saturated fuel canister is a bit like a supercharged engine waiting for a spark.

BOOM! I guess using nitrogen is probably safer. Not sure if I'll gain access to nitrogen gas for the Camry, we'll see.

Good idea on the turkey baster. I'll have to get my own, the :Princess: would be :mad: if our turkey started tasting like brake fluid :rant:

:D

AxleIke
07-30-2013, 05:45 PM
You can use CO2 as well. Doesn't have to be nitrogen.

Rzeppa
07-31-2013, 07:19 PM
You can use CO2 as well. Doesn't have to be nitrogen.

I always use acetylene :lmao:

AxleIke
08-01-2013, 06:15 PM
:D

Would also work actually. Doesn't provide the dilution of inflammable material with a non combustible gas the way Nitrogen and CO2 would, but it still displaces oxygen, which is what you really want to avoid.

rover67
08-01-2013, 10:13 PM
please don't try to fill something with acetylene and think that it won't blow up just because it displaced the oxygen.... it won't work actually.

It don't need no o2 to pop. (redneck voice)

you ever tried it?

pretty impressive.

very unstable in gaseous form.

very.

Rzeppa
08-01-2013, 11:10 PM
please don't try to fill something with acetylene and think that it won't blow up just because it displaced the oxygen.... it won't work actually.

It don't need no o2 to pop. (redneck voice)

you ever tried it?

pretty impressive.

very unstable in gaseous form.

very.

My comment was intended to be very, VERY much in jest. All the years I was in regulatory affairs doing compliance work, among the things I had to do was all our explosion-proof designs. In CSA and in NFPA stuff, the reference gas was always acetylene, as in, the most explosive, destructive gas you could frigging come up with. As in, even more than pure hydrogen.

Look at it cross-eyed and it will blow up. BOOM!

My good buddies from the Lone Star Land Cruisers in Texas told me stories about how you can take a big a$$ trash bag, fill it up with acetylene from Joe-Bob's welding rig, stuff it into Daisy-May's old abandoned washing machine we dumped down there in the hollar, and when we shoot at it with our deer rifles and that there washer would shoot a hundred feet up in the air! Yee haaaaaa! :thumb: