Removing carbon canister, fuel evap. emissions

08-25-2005, 06:01 PM

Hi,

Was wondering if anyone could enlighten my as to what I need to consider when
removing the fuel evaporative emissions system, i.e the carbon canister -- my supra
has a Japan import motor I put in it , and it does not have the EGR system, nor do I
believe it to be setup for fuel evaporative emissions system. Can removing this cause
problems with the car of how it runs?? Do I need to plug up some vacuum lines, or the one
coming off the throttle body?

Also, what can happen if the evaporative line from the fuel tank got clogged and then I realized it a few days later -- can that mess up the fuel pump or fuel pressure regulator??

My car is having a couple issues, and I'm trying to troubleshoot it. Right now it won't stay
running for more than a couple seconds, and it will rev up and down a few times and then knock off. Seems like some kind of crazy fuel pressure thing going on.

Help :huh:

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).

Rahul · 09-17-2008, 06:58 AM

hi guys ... i have a 1jz-gte 1992 toyota supra. lately after i start the car in the morning ... and drive it for 5 minutes, it misses very badly and dumps out a lot of fuel out of exhaust pipe and there is a rich fuel smell inside the car. i changed all the coils and the plugs and got my car scanned. nuthing came out. can it be caused by the excessive pressure in the tank as the cap might not be able to release the excess pressure or its the charcoal cannister. the only thing is it only happens when i drive my car 5 minutes in th emorning and after it does so if i park it for 15 mins and start again it runs fine all day no matter how much and many times i park it and restart it, next morning its the same thing ... pleas ehelp .. thanks

09-17-2008, 06:58 AM	#3
Rahul Stock Join Date: Sep 2008 Location: north vancouver Posts: 3	charcoal cannister hi guys ... i have a 1jz-gte 1992 toyota supra. lately after i start the car in the morning ... and drive it for 5 minutes, it misses very badly and dumps out a lot of fuel out of exhaust pipe and there is a rich fuel smell inside the car. i changed all the coils and the plugs and got my car scanned. nuthing came out. can it be caused by the excessive pressure in the tank as the cap might not be able to release the excess pressure or its the charcoal cannister. the only thing is it only happens when i drive my car 5 minutes in th emorning and after it does so if i park it for 15 mins and start again it runs fine all day no matter how much and many times i park it and restart it, next morning its the same thing ... pleas ehelp .. thanks

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08-25-2005, 06:01 PM	#1
pdogg Guest Posts: n/a	Hi, Was wondering if anyone could enlighten my as to what I need to consider when removing the fuel evaporative emissions system, i.e the carbon canister -- my supra has a Japan import motor I put in it , and it does not have the EGR system, nor do I believe it to be setup for fuel evaporative emissions system. Can removing this cause problems with the car of how it runs?? Do I need to plug up some vacuum lines, or the one coming off the throttle body? Also, what can happen if the evaporative line from the fuel tank got clogged and then I realized it a few days later -- can that mess up the fuel pump or fuel pressure regulator?? My car is having a couple issues, and I'm trying to troubleshoot it. Right now it won't stay running for more than a couple seconds, and it will rev up and down a few times and then knock off. Seems like some kind of crazy fuel pressure thing going on. Help :huh:

08-26-2005, 06:17 PM	#2
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).