Removing carbon canister, fuel evap. emissions

SupraDave · 08-26-2005, 06:17 PM

Here's an article about the charcoal canister that I came across when I was having a problem with mine. It turned out to be that a vacuum hose was routed incorrectly.

--If you are smelling fumes inside the car then more than likely the little VSV valve
on the thermostat housing that one vacuum line from the charcoal canister runs to
and the other line from the throttle body runs to (the plastic piece that ALWAYS
seems to break just before smog inspection) has failed and is not allowing vacuum to
the charcoal canister to "remove" the vapor from the canister.
When the canister is disconnected is just eliminates the feed to the canister which is
why there are no more fumes. The fuel tanks in cars are vented to prevent pressure
buildup within the tank (not good).
The charcoal canister was added for smog reasons where as old gas tanks used to
have vented caps that would just vent to the atmosphere.
Newer cars have "sealed" tank systems and a vent hose on the top that runs to the
charcoal canister.
If you do remove your canister DO NOT plug the line coming from the fuel tank.
Leave it open (this is what I did where the metal line from the fuel !
! tank connects to the rubber hose just below the brake master cylinder. If you plug
the line,
1) You will NEVER be able to fill the tank up completely,
2) You will have pressure inside the fuel tank that can cause cavitation in the
fuelpump, and the least important
3) You can cause a potential explosion. :-) (OK if it is a Honda but not
recommended for a Supra).
-Dean Marcum (VERY bored at work)
Charcoal canister removal. The charcoal canister is the black cylinder that sits on the
passenger side in the back of the engine bay. It filters excess gas pressure so that it
can be vented to atmosphere safely. You can leave the line unplugged and very little
gas fumes will come out. Or, if you are worried about fumes, run some more fuel line
from there to a hole in the frame rail straight down from where the canister used to
be. Its covered with a plastic cap. Remove the charcoal canister. Plug up the vacuum
line that goes to the AFM bracket to the thermostat housing bracket to the throttle
body. You might as well remove all those lines and plug it up as close to the throttle
body as you can. This wont really do much except give you a little more space to put
stuff (its a decent location for a PCV catch can).

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08-26-2005, 06:17 PM	#1
SupraDave Stock Join Date: Jul 2005 Posts: 11	Here's an article about the charcoal canister that I came across when I was having a problem with mine. It turned out to be that a vacuum hose was routed incorrectly. --If you are smelling fumes inside the car then more than likely the little VSV valve on the thermostat housing that one vacuum line from the charcoal canister runs to and the other line from the throttle body runs to (the plastic piece that ALWAYS seems to break just before smog inspection) has failed and is not allowing vacuum to the charcoal canister to "remove" the vapor from the canister. When the canister is disconnected is just eliminates the feed to the canister which is why there are no more fumes. The fuel tanks in cars are vented to prevent pressure buildup within the tank (not good). The charcoal canister was added for smog reasons where as old gas tanks used to have vented caps that would just vent to the atmosphere. Newer cars have "sealed" tank systems and a vent hose on the top that runs to the charcoal canister. If you do remove your canister DO NOT plug the line coming from the fuel tank. Leave it open (this is what I did where the metal line from the fuel ! ! tank connects to the rubber hose just below the brake master cylinder. If you plug the line, 1) You will NEVER be able to fill the tank up completely, 2) You will have pressure inside the fuel tank that can cause cavitation in the fuelpump, and the least important 3) You can cause a potential explosion. :-) (OK if it is a Honda but not recommended for a Supra). -Dean Marcum (VERY bored at work) Charcoal canister removal. The charcoal canister is the black cylinder that sits on the passenger side in the back of the engine bay. It filters excess gas pressure so that it can be vented to atmosphere safely. You can leave the line unplugged and very little gas fumes will come out. Or, if you are worried about fumes, run some more fuel line from there to a hole in the frame rail straight down from where the canister used to be. Its covered with a plastic cap. Remove the charcoal canister. Plug up the vacuum line that goes to the AFM bracket to the thermostat housing bracket to the throttle body. You might as well remove all those lines and plug it up as close to the throttle body as you can. This wont really do much except give you a little more space to put stuff (its a decent location for a PCV catch can).