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What is this & what does it do?


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18 replies to this topic

#1 Bratmobile

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Posted 08 July 2013 - 03:37 PM

  I've had a bunch of vacuum leaks recently fixed, and was wondering ( maybe a stupid question) what's the part I've got circled in the photo?

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#2 TIMBERTIGER

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Posted 08 July 2013 - 04:02 PM

Charcoal canister. Has something to do with emissions. Junked all mine and deleted emissions.



#3 Tsuru

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Posted 08 July 2013 - 04:12 PM

:o

How environmentally irresponsible of you!!!

 

(you deserve a cookie!)

 

:P



#4 Bratmobile

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Posted 08 July 2013 - 04:35 PM

Charcoal.....Hmmmmm. Maybe I'll use it for my fish tank.



#5 Bratmobile

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Posted 08 July 2013 - 04:36 PM

BTW~Thanks for the info



#6 pressingonward

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Posted 08 July 2013 - 10:05 PM

The charcoal canister is essentially the vent for your gas tank. It absorbs gas vapors when the gas inside the tank expands (like on a hot day) and stores them. When you drive your car a vacuum line sucks the fuel vapor out of the charcoal and into the engine where it is burned.

 

There is NO reason to remove the charcoal canister. It does not hurt your engine's performance in any way, and it captures raw fuel that would otherwise escape into the atmosphere.



#7 Tsuru

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Posted 08 July 2013 - 11:23 PM

they can get old however and lose efficiency, becoming just a canister that has some old charcoal in it..

Absorption rates decline over the years to the point of uselessness, Yes, it is supposed to help keep fuel vapors out of the atmosphere, (when fairly new) and yes, it actually can (very marginally) help with (ever so slightly) increasing the mixture (useful during cold starts) but after a few years they are just pieces of equipment that no longer really work "as advertised".

 

hence the environmental slam.

 

Otherwise I concur, They aren't in any way a drag on the engine, 

and if it came with it, why not use it.

 

I'm not a fan of deleting emissions items, but am appalled at the prices for replacing said items.

Canisters are not cheap, starting at around $50 and going up from there for a plastic box with charcoal in it!

and neither are cats. $65 and up to hundreds.

granted, you only have to do it once, and compared with what we are all used to doing here, the labor is a non issue.

 

My suggestion is that if you are going through the trouble to keep it, Why not replace it with a good fresh one?

unless you just want it there for looks.

 

or to smuggle things in...

 

yup...

 

heehee,

timothy



#8 -tombba-

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Posted 09 July 2013 - 05:16 AM

Charcoal.....Hmmmmm. Maybe I'll use it for my fish tank.

 

No don't kill your little fishes :) It's been in the engine bay for years and for sure has collected a lot of nasty stuff that is not supposed to go into your fish tank at all.



#9 TIMBERTIGER

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Posted 09 July 2013 - 03:43 PM

I deleted mine when i did my Weber conversion only because I like to keep it as clean and simple as possible under my hood so I removed all non-mission essential equipment. Since my vehicles are licensed in Idaho i don't worry much about emissions.



#10 Gloyale

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Posted 10 July 2013 - 11:17 AM

When your tank vapor locks because you don't have a vent.....

 

Or the vent line spews liquid gas on a hot day from expansion......

 

You will understand why it was there, and why you should leave it there.



#11 djellum

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Posted 10 July 2013 - 11:46 AM

not to hijack too much, but a question.  is there any pitfalls when installing a vented gas cap so you can plug off the tank vent hose?

 

after removing mine once I did the weber swap, I just left my tank vent open.  I havent had a single issue with it that way, but I dont like it on general principle.  is there a certain pressure level to achieve or avoid, or just buy any old vented cap that fits?  



#12 TIMBERTIGER

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Posted 10 July 2013 - 08:54 PM

Been driving it that way for 10 years with no problems. it would have to expand a ridiculous amount to push liquid fuel clear out of the line in the engine compartment.



#13 Gloyale

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Posted 11 July 2013 - 12:40 PM

Been driving it that way for 10 years with no problems. it would have to expand a ridiculous amount to push liquid fuel clear out of the line in the engine compartment.

 

It expands almost 1.5% for every 10 degrees temp rise

 

You probably don't drive with a full tank much.

 

Fill up to the top on a HOT day and it WILL spew liquid.

 

But I am probably wrong, and FUJI and all other car makers put the evap canisters in there for no reason at all, to increase production cost, and we are all stupid for having them in our cars and should all rip them out willy nilly because we don't know what they do.



#14 ferox

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Posted 11 July 2013 - 01:34 PM

Been driving it that way for 10 years with no problems. it would have to expand a ridiculous amount to push liquid fuel clear out of the line in the engine compartment.

 

It has happened to me.  When I Webered my wifes '84 in the summer I initially left the vent hose unconnected, with a full tank it started dumping a lot of gas out of the hose in the heat of the day.  So much gas poured out and evaporated on my driveway, that I thought I got hit by a siphon-thief.  I refilled and had the hood open when it started doing it again, so I figured it out pretty quickly, but I was surprised at how much gas pumped out.  The elevation of the hose was greater than the elevation of the tank, so it didn't prime it just expanded.



#15 TIMBERTIGER

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Posted 11 July 2013 - 11:04 PM

It has happened to me.  When I Webered my wifes '84 in the summer I initially left the vent hose unconnected, with a full tank it started dumping a lot of gas out of the hose in the heat of the day.  So much gas poured out and evaporated on my driveway, that I thought I got hit by a siphon-thief.  I refilled and had the hood open when it started doing it again, so I figured it out pretty quickly, but I was surprised at how much gas pumped out.  The elevation of the hose was greater than the elevation of the tank, so it didn't prime it just expanded.

 

 

What keeps liquid fuel from pouring into the charcoal canister when the systems hooked up normally? If i filled up on a HOT day the fuel would already be expanded. Whats the best way to let a tank vent without a canister and without danger of overflow? Maybe since I don't "top off" I just stop filling when it clicks, there is enough room for expansion.


Edited by TIMBERTIGER, 11 July 2013 - 11:13 PM.


#16 Tsuru

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Posted 12 July 2013 - 12:23 AM

The canister is never supposed to even see raw fuel.

It's designated purpose it to trap the VAPORS vented off the tank. If there is raw fuel in the canister because of expansion then the tank was overfilled, OR there is something wonky with the line being able to pick up fuel instead of just worrying about the vapors.



#17 Gloyale

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Posted 12 July 2013 - 10:55 AM

The charcoal canister will see raw fuel sometimes in normal setup.  Just not supposed to be much, and it will ussually only happen on a hot day with a full tank.  Will only happen if the tank is FULL up to the filler neck.

 

Gasoline is stored in tanks in the ground.....it is much cooler underground than outside in the sun on a hot day.

 

When you pump it into your tank it expands.



#18 ferox

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Posted 13 July 2013 - 11:46 AM

What keeps liquid fuel from pouring into the charcoal canister when the systems hooked up normally? If i filled up on a HOT day the fuel would already be expanded. Whats the best way to let a tank vent without a canister and without danger of overflow? Maybe since I don't "top off" I just stop filling when it clicks, there is enough room for expansion.

 

Yeah the question about raw fuel in the canister was one I had as well when I realized what was happening.  I wasn't concerned about liquid fuel getting to the canister so much as the amount that could potentially get to the canister.  I replaced the canister system and kept an eye and nose on it, but never had a problem.  It's not ideal, but it will all go away when I EJ, so I left it alone.  That car also had a bit of a rake to it's stance, which probably changed the angle of the gas tank, so the fuel tank was sloped toward the front of the car and may have contributed to the vent line discharge.

 

As far as your other questions, I think the vented gas cap is still probably the simplest option.  With a vented cap the filler neck should act as a small reservoir for the expanding fuel.  As Gloyale mentioned, the tanks at the fueling station are underground so they're significantly cooler.  They're also between 5,000-10,000 gallons in capacity and double-walled at a minimum, so the temperature of the liquid fuel underground stays a lot cooler on a hot day.  There could easily be a 30-40 degree difference in temperature between the station fuel and the fuel in your tank.



#19 TIMBERTIGER

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Posted 13 July 2013 - 12:23 PM

I think I am going to try and find a vented cap just to be safe. Then I could probably get away with capping off the line in the engine compartment. This way if it ever does vent, it wouldn't be right by the power plant.






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