Coal canister???? What is it ????

[Basher]

I have just begun a major job on my Wag and we just took a look at the coal canister, and I want to know what it does, can I clean it(the filter at the bottom is reaaly dirty), can I buy a new one, if so where???

[coolram]

The charcoal canister is there to filter fuel vapors from your carb and the fuel tank.It's very important to have this functioning as many will atest to.The filter element on the bottom of the can(it fits on the bottom outside)is replaceable.The charcoal can be replace with filter charcoal used for fish tanks or used in grease/air filters for range hoods.

[Don in Missouri]

So how do you know when the charcoal needs to be replaced? The one on my '86 was replaced a few years ago, but it has been submerged in mud since then. I haven't tried to take one apart. Is there a trick to it?

Can they cause poor engine performance, or is it just an odor nuissance when they quit working. I have considered retrofitting one to my '78 with 1406 Edelbrock, because it sure does smell a lot.

[coolram]

Well the odor is annoying but the main reason it's there is to capture fuel vapors and prevent them from building up under the hood.

[Wart Hawg]

Would it be possible to pop some "speed holes" in the hood to vent the vapors? My canister seems to be missing. :D

[coolram]

You could do that or buy a replacement canister(maybe find one in the bone yard and rebuild it).

[Desert Beast]

the smog nazis in CA have required me to have one. she passed smog no prob but since there wasnt a evap canister they failed me on the visual. i found one at a junk yard and it cost me 80 bucks :mad: . just need to plumb it in.

[LHopper]

On my 78 there is no canster that I can find, and I was able to pass. I don`t think that they all came with them. and I don`t need to run a cat, that was at a "test only" station.

[Desert Beast]

ihopper, mine doesnt have cats either but the book said that it was suposto have a canister. cant find a place to mount it. the mount from the one that i bought wont fit anywhere. wondering if it ever had one.

[Chero77]

Federal emissions FSJs did not get cats or EVAP systems until '78. California FSJs got them at least as early as '77 as the '77 TSM shows them as being so equipped. My Federal emissions '77 does not have charcoal cannister or a cat and I was able to pass smog with no problem. The smog guys check the emmissions sticker on the air cleaner and then check a book they have to see whats supposed to be on the car.

Oh, yeah, when the engine is hot at idle fuel will boil in the float bowl and vent through the carb. Without an EVAP system, you can smell this inside the car (or at least I could). So I went to a chrome open element air filter on the theory that any boiled off vapor would immediately get sucked back into the carb. That was two years ago and so far its worked fine as I haven't ever smelled fuel vapor again.

[ January 01, 2003, 02:37 PM: Message edited by: Chero77 ]

[Desert Beast]

my chero is federaly smogged. does this mean that i shouldnt need a canister. the book that the smog station has said that i didnt need a cat but needed a canister. could they be wrong?

[Merc69]

Along the same line...do you have to retain the canister for any performance reasons? In FL we don't have any smog police and no inspections. My brother a properly trained mechanic looked at the shop maunal and because we are eliminating the EGR valve (Non EGR Edelbrock intake)he said to pull the canister and the lines running back to the fuel tank. Cap the ends of the tank and look at the extra space on the fender as a place to put that On Board Welder I have an eye on :D

[Rogue]

my Chero was originally from CA and as a 74 model it has a charcoal canister.

the charcoal canister capture fumes from the carb and gas tank to prevent them from being vented into the atmosphere - the fumes are then introduced via a switch to the induction system on a warm engine during acceleration ( off idle )

merc69 - you can eliminate no prob just be sure to vent your gas tank somehow to prevent a vacuum lock

[Chero77]

Originally posted by Desert Beast:
my chero is federaly smogged. does this mean that i shouldnt need a canister. the book that the smog station has said that i didnt need a cat but needed a canister. could they be wrong?According to the '77 TSM, a federal emissions Chero does not have either a cat or an EVAP system (charcoal cannister). Mine has niether and I passed smog at a "test only" station, just two months ago. I think your smog station is wrong.

[Chero77]

Also, if your rig was originally a QT, you don't have to run it on the dyno. Mine is converted to part-time and thus could be run on the dyno which is what the smog guy was going to do, but I pointed out to him that QTs were exempt from dyno testing. The smog guy didn't know, most don't. If they see locking hubs they just assume it goes on the dyno, so you will need to point that its exempt. The AQMD exempts all full-time 4x4's from dyno testing and has a list of them by year and model. Our QTs are on the list. It helps if you have a quadra-trac emblem somewhere on your Jeep. I got an emblem from a junkyard on put it on the tailgate just so I could point to it during smog checks.

[crazyguy]

my pickup had the emisions crap removed by previos owner(i finished the job by removing most of the vacuum lines leaving me with nothing other than power brake vaccuum, vac advance, and an egr vac which dosn't do much cause I dont have enough back pressure for the egr). the tank vent would have originally gone to the smog can, wondering if I should run the vent lines to a vac source

[Desert Beast]

Chero77, with regaurds to the dyno Q, mine is converted to part time w/ a dana 20 but i almost had the guy convinced but his computer said that i needed to take it to a all wheel dyno somg place. i dont know man this smog crap is too **** complicated. where did you go to get it smogged. somewhere local. wouldnt mind taking it there. a name and address would be appreciated.

[Chero77]

Desert Beast, I took mine to:

ALL SMOG
18411-B Hawthorne Blvd.
Torrance, CA 90504

Ph. 310-542-1797

I think your smog guy doesn't know what he is doing. If its a QT its exempt from the dyno. AQMD exempts full time 4WD vehicles from dyno testing and 73-79 QTs are on the list. I have seen the actual list AQMD uses. Also, I specifically called AQMD and asked before I went in for my first smog check. The list may also be on the AQMD website. Also, no federal '77s had EVAP systems according to the '77 TSM. I say its definitely time to find a competent smog guy.

Both times I have gotten my truck smogged, the tech guy had never heard of a QT, which is not surprising, but once I told them what it was and they checked their spec books, they agreed that it was exempt from the dyno test.

[Desert Beast]

thanks for the info but the computer system that the tester is linked to is the one that said that i needed to take it to a all wheel dyno place not the guy. and for the canister the book he had said that it was required. maybe it was an outdated book or something, i dont know. ill go to this place and see.
thanks a bunch.

[Bob Barry]

In '78, the 49-state trucks didn't have the evap canister or the catalytic converter. '79 was the year these became universal.

My '78 doesn't have the Evap canister, but I wish it did. It's a clean place to vent the fuel-tank and the fuel-bowl, and it doesn't hurt performance, as long as it isn't broken.

The filter in the bottom can be replaced very cheaply.

I think it's just a regular GM-style canister. In fact, paging through an AC-Delco carb book, I came across the GM part # for a repair kit to replace the rubber diaphragm under the vacuum port on the canister. I wonder if that's still avaiable...