I'm running a 90-92 Camaro EVAP canister in my EFI converted 2nd gen, as closely mirroring the 3rd gen overall EVAP setup as possible. Been running it like that for the last ~15 years or so and seems like it's worked fine all these years.

Today, I filled up the tank and drove a few miles, came home and got a horrendous whiff raw fuel odor emanating from the EVAP canister area. I mean it was STRONG... I actually smelled it first when I pulled up into the driveway at home while still sitting in the car. Up to this point I've never had that happen before. Freaked me out since I actually thought I had some sort of bad fuel leak under the hood some place.

I opened the gas cap and no hissing sound, so it seems like the system is working in terms not allowing fuel vapors to build up.

I'll probably run an electrical test on the EVAP solenoid soon to verify it's operation nonetheless.

So I'm questioning if the EVAP canister itself may actually be a consumbale item such that it can go bad after a while. It was used when I bought, so who knows how many miles it had on it prior.

Since it's a 3rd gen canister, figured I'd ask the 3rd gen guys!

 

I read something about a Silverado accepting fuel very slowly and the fuel cap hissing when opening that it could be the foam filter near the solenoid being clogged up. I am not sure that there is a foam filter before the charcoal cannister or not on our cars. I think you will find that there is not a replacement for the charcoal cannister. But, I read on a U Tube that you could cut the charcoal cannister open and replace the charcoal with material from an aquarium shop. I was thinking that when I get a chance that I might open mine up and replace the charcoal. Look up on a couple of U Tubes and see what you think? Please let us know what happens.

 

hmmm.... I can get used ones on ebay for ~$30 shipped. I may try one of those first if that's the case.

But yeah, I've heard about replacing the charcoal as well with that process.

I don't have any kind of filter inline with the canister...

 

Well, a 12V battery across the solenoid confirms that it works.

This stupid EVAP canister is going on 30 years old.

Does anyone sell new ones? I checked Summit, RockAuto, and Autozone. Nothing so far...

 

The charcoal inside will eventually stop accepting new vapors, become "saturated". Some cars have the charcoal is removable/replaceable as a packet.

DSE buys a BMW canister. It's very nice, but expensive
https://www.bmwdirectparts.com/oem-p...er-16131180463

 

You might want to install an inline fuel filter in the vacuum line going to the charcoal canister to prevent any bits of charcoal from being sucked into your throttle body and/or engine.

 

Holy crap... I can find better things to spend $250 than a vapor canister... lol.

I took some compressed air and was blowing gently through the vacuum lines and vapor lines through the canister with the solenoid activated and deactivated... no blockages or anything.

I'll have to keep investigating...

 

That's actually a good thought

 

Years ago, somebody posted on here about rebuilding it with aquarium filter activated charcoal.

Search the site for "aquarium", shouldn't be too terribly many irrelevant results.

 

Yep, I saw that. My issue is the catastrophic nature of it...

I can see starting to get a small whiff of fuel as the charcoal starts to become less effective.... but I literally went from nothing to smelling like an open fuel tank inn no time flat.

 

I rebuilt one. Worked out well. Here is the link
https://www.thirdgen.org/forums/tech...ebuilt-my.html

You could have easily just overfilled the tank a bit. Excess fuel could have gotten up into the evap line and been drawn into the canister. I would just check thoroughly for raw fuel leaks and drive it. Check again next time you fill up.

 

Double check that you didn't disable purge in the calibration. One time I did that then forgot until weeks later it was the same, a huge whiff of fuel. So much so, just like you, I pulled over and checked for a fuel leak. Took a few days before it dawned on me to check the calibration.

The solenoids do fail, so using a mity vac and ground to check it works.

RBob.

 

Good point RBob... I just did a bin compare in TP between my bin and AUJP. No changes. But good to cross that off the fault tree...

I'll double check the solenoid... I didn't use a vacuum pump last time, so I'll try that.

 

On my car i removed it and I hear the charcoal if i shake the canister i am wondering Dose this make this bad

 

After reviewing Aaron R's thread, it seems to me that it should be relatively easy to fabricate your own charcoal canister using a catch can for the container. A container that screws together would be great so you can periodically change the charcoal. I will have to look into this.

 

I know it is a different car but I have seen a couple of good U Tubes on this subject. Granted different cars but basically the same idea.

 

I borrowed these pics. But the idea would be to fill the lower portion with charcoal.
I actually found a carbon canister: https://www.usplastic.com/catalog/it...?itemid=129209


Here is some more good info: http://www.gmcmhphotos.com/photos/ca...n-brack-7.html

Autozone has this: https://www.autozone.com/engine-mana..._0_0?rrec=true

 

The Autozone one doesn't have the solenoid on it. I guess you'd have somehow adapt it on.

I actually went to the pet store today and bought some activated charcoal. Probably will attempt the rebuild tomorrow.

 

Check the canister body it might be cracked. After 30+ years they will dry out and become brittle.

 

They have the associated parts also: https://www.autozone.com/searchresul...oal%20canister

 

Yeah I'm sure I could probably adapt the parts, but I'd rather stay with the factory system which I know works.

 

On 90-92 Camaros, can someone please tell me where the tube marked "Air" goes on the EVAP canister? Currently I have it open to the atmosphere as I thought I saw it that way on 1991 Camaro one time.

If I blow through the "Tank" line with the solenoid closed, air comes out the "Air" line. That seems counter intuitive to me. Wouldn't the vapors simply bypass the valve in the solenoid?

I cut the canister open this morning and the "Air" tube just goes straight into the reservoir of charcoal. Since the EVAP can has no opening on the bottom side, I guess this must serve the same function as the bottom side opening on previous model year canisters?

The charcoal wreaks of fuel... probably totally saturated.

 

Well, you know what you have to do then........................

 

Lol... Yep. Matter of fact it's all rebuilt and JB-welded back together. Just waiting for it to cure.. I'll sand it, give it a coat of black paint and then re-install and see what happens.

Though I'm still curious what the answer is to my question in post #22 above.

 

Very interested. Please let us know!! thanks.

 

The AIR tube is open to the atmosphere. On some installations GM ran a hose to it, then the base of a T into the fender area. The T then had a hose on each end, one up and one down. Open ended hoses.

The CCP system works by pressure building up in the fuel tank. This puts pressure on the vapor control valve which then opens allowing fumes to enter the charcoal canister. The charcoal absorbs the fuel in the fumes while the scrubbed air exits the canister via the AIR port.

The solenoid is used to purge the canister of fuel. When it opens and the throttle is opened (ported vacuum), air enters the AIR port as the engine vacuum draws it through the canister picking up the fuel. Which enters the throttle body as fumes and is burned in the engine.

RBob.

 

Thanks for the detailed explanation RBob!

 

Wow, what a difference. Been so busy I haven't had a chance to drive the car for the last few weeks....

But I came home from a lengthy drive today; not only was there not even the slightest hint of fuel smell, but the car just overall smelled cleaner after pulling into the garage.

Opened my hood and put my nose right up to the charcoal canister... yeah, not even a whiff of fuel.

Definitely recommend going this route to refresh the canister!!