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I have a 1973 Wagoneer with the stock 360. I have searched for a replacement charcoal canister, but have not found one that matches the original exactly. The original canister has only two ports, tank and purge, and is open on the bottom with a filter to take in fresh air. Seems to me that any replacement canister with the same two ports would work just fine? The difference in the ones I'm seeing is that they have a small fresh air inlet on top of the canister instead of a large opening on the bottom. Does this matter at all? Would it have any negative impacts? I am trying to get rid of persistent fuel smell in the garage.

I know some have opened up their original canisters and replaced the foam filters and activated charcoal, but that would be my last resort. Has anyone found a compatible new canister that is generally available? Thanks!

Pretty sure the early canisters are entirely 'passive' in that there is no control of some type of valve by engine vacuum, and they depend on a draft (Bernoulli effect) from the original air cleaner to purge. Vapors come from the tank and exit through the charcoal bed, where they are adsorbed to the charcoal. When the engine is running, a modest vacuum from the air cleaner draws air into the bottom of the canister and the charcoal releases the fuel vapor and it is drawn into the engine with the air. The pad on the bottom keeps out mud and water. I expect this design won't work without the big opening.

The later canisters have a valve inside and are purged by engine vacuum. I believe this allows the smaller air intake, since the engine vacuum is strong compared to the air cleaner draft, and the engine can purge through the smaller opening. I understand that the valve in these later canisters switches between a small and large purge (there is always some purge while the engine is running), and the switch is needed to manage the effective vacuum leak that the canister causes.

Can you use a canister from another application? Sure, I've done it. Works fine. However, I used a later style canister for an application that came with the later style devices. Certainly to use the early style, you will need the factory air cleaner. I expect you will also need a canister with the big opening.

Thanks for your view Tim!

I'd also mention. you can use the later style 'active purge' canister on an earlier vehicle. Vent line, purge to the PCV hose, and ported vacuum for purge signal.

I’ve used ‘94 yj canisters in two fsj’s now. V8 and i6. I’m pretty sure the number on top has been superseded but that’ll get you headed in the right direction.

k.

Tgrease, now I know how a Vapor canister works. It was a mystery to me before. Your better than Google

Thanks guys, I appreciate the additional information!

kris wrote: ↑Sun Jan 07, 2024 6:20 pm I’ve used ‘94 yj canisters in two fsj’s now. V8 and i6. I’m pretty sure the number on top has been superseded but that’ll get you headed in the right direction.

k.

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NB I used the same style canister from an XJ for my J20. When I did this, these were available new on the aftermarket; a quick look only found used ones now. Possible new ones are still available if you search the part numbers you find on the used examples.

This device is good since it has the three connections you need for the gas tank (vent, purge, purge signal) and has the same general size and shape as the original FSJ canister. Should pass inspection, if that's an issue. It's for an EFI vehicle, so it has no connection for the carburetor bowl vent. If your application needs that, you could perhaps tee into the tank vent if your bowl vent solenoid is present and working.

Note also that other manufacturers put the purge valve in a separate location and maybe not vacuum controlled (ie Chevrolet). You'd need a little more thinking/plumbing to use their devices.

Glad if I could help.

tgreese wrote: ↑Mon Jan 08, 2024 9:23 am
NB I used the same style canister from an XJ for my J20. When I did this, these were available new on the aftermarket; a quick look only found used ones now. Possible new ones are still available if you search the part numbers you find on the used examples.

This device is good since it has the three connections you need for the gas tank (vent, purge, purge signal) and has the same general size and shape as the original FSJ canister. Should pass inspection, if that's an issue. It's for an EFI vehicle, so it has no connection for the carburetor bowl vent. If your application needs that, you could perhaps tee into the tank vent if your bowl vent solenoid is present and working.

Note also that other manufacturers put the purge valve in a separate location and maybe not vacuum controlled (ie Chevrolet). You'd need a little more thinking/plumbing to use their devices.

Glad if I could help.

Correct on not having the bowl vent connection. These pics are on an i6 running Howell tbi. On my old wagon with the carb I had the bowl vent hose plugged internally as the 2150 vents inside the air cleaner. The bowl vent hose was tee’d into the pcv. It looks stock and always passed visual in California. I really feel like most of the techs now just don’t have the experience or patience to really dig thru the engine bay to confirm every hose.
A little bit of google should turn up a few options for a canister.

k.

kris wrote: ↑Mon Jan 08, 2024 10:01 am ... I really feel like most of the techs now just don’t have the experience or patience to really dig thru the engine bay to confirm every hose.
...

Yep, more than that. IME the inspection stations aren't keen on finding problems they can't fix for profit. I was friendly with my local parts store and shop (since out of business) that did a lot of inspections. Chatting with the lead mechanic, he admitted that their main reason for offering inspections was to bring in business for the shop. They made no money on inspections, not even the easy easy ones. Not much money to be made sorting out the vacuum plumbing on a 50 year old oddball vehicle. I'd expect the visual to be perfunctory, though you'd still have to pass the tailpipe test.

The state here puts a lot of effort into policing the inspection stations, with frequent reviews and visits from regulators, and video tape of every inspection. I suspect that's one of the reasons my local shop quit the business.

My state didn’t want to police them and just stopped doing them 25+ years ago. No emissions test either.

If this has been addressed, I apologize. I’m hoping to resolve blow by on my J10 il6. I have new PCV coming and charcoal canister filter. Can the charcoal be replaced?