Suggestion for missing Charcoal Canister

This is it. This is the weekend I should be able to start up the Bronco for the first time in 9 months-ish!

I’m taking stock of a few things and looking at all the old emissions stuff I have removed and realized I somehow have misplaced (likely tossed) my Charcoal canister for the fuel vapor. Any suggestions on how to handle the currently wide open vent in the bay?

I kept one on my truck for venting.

Junkyard or U Pull It.

Even if I grabbed one somewhere, I’m not sure how I’d set it up - now that I’ve converted to a sniper EFI, most of my old vacuum lines and checks are gone. I’m hoping there’s simple set up. I’ve been searching online but the info is all over the place - I saw one unfortunate forum post (not here) where someone suggested just attaching the vent hose directly to the air cleaner...

I’m thinking maybe getting some sort of vacuum triggered valve that hooks up to the PVC valve for actuating? Does that even make sense?

Oh ok, I used what I had and made it work.

Yes going to the PCV makes sense to me. You could even put a small filter on the line to keep dirt out. But you would get the gas smell, which is why I cobbled mine together.

FrazerJames wrote

I’m thinking maybe getting some sort of vacuum triggered valve that hooks up to the PVC valve for actuating? Does that even make sense?

 
Your EFI is a sealed system, so you are looking for an evaporative emissions canister for the fuel tank vent(s)
Vacuum needs to be applied to the canister, but not the fuel tank.
I think that's why these controls have 3 ports.


So if you had (A) tank, (B) canister and (C) vacuum
A would be connected to B except when vacuum was present at C.
In which case A is isolated and B & C connect, correct?

Yes, I believe that’s right. I’m just not sure if anyone had figured out an alternate set up that I can pull that off without a canister. I saw some posts on another forum about an inline vapor filter, but I can’t find it anywhere searching.

Without a canister you're not collecting or storing any vapors.
And you can't really leave your tank sealed because of pressure changes.

Canisters are available new from $20 on up to a couple of hundred, but I'd think any one for a vehicle with similar fuel capacity would be workable.
I just saw a SMP one on Summit for $30, but Dorman, Stant and many others sell them too.

It's just that valve (or solenoid💡) that is key.

Rusty is always talking about all the things the Sniper can control.
If you could have an output trigger a solenoid.... just like the EGR is controlled on later I-6's it would be perfect.
Engine warm, under cruise = not much demand for an accurate A/F ratio.

I actually still have the purge valve - although I have no idea how I’d hook it up now without the original lines hooked up. I bought a new canister so that’s covered at least...

Do you think hooking the purge valve up to the PCV line would get me somewhere?

The PCV will definitely suck the vapors pout of the canister, if connected.
But what do you connect the third port of the purge valve to?

I don't know enough about the Sniper system.
Rusty goes on about how Holley instructs not to have any emissions controls connected.
But it's best to have a vapor recovery system triggered at operating temperature, and most of the routing diagrams I've seen seem to have a vacuum delay valve in the system as well.

I am going to admit my ignorance here.

I don’t believe there’s a vacuum trigger for that on the Sniper that I’ve seen.

I mean, is it bad to have it on constant while running? I get that it would be better to have it trigger at temperature, but I can’t imagine it takes very long to burn off anyway or exhaust out during start up.

It would be more like an operating temperature sensor triggering the solenoid when under x throttle position.

I dont know if you would want some of the PCV vacuum diverted all the time.
That would reduce the draw through the crankcase, which is eliminating water vapor and keeping the seals from leaking.

Like I said above, I don't know anything about the Sniper, and I don't know much about the 300.

I definitely appreciate you walking me through some options either way!

All,

As I cleaned my engine bay from whatever I did not find important anymore, in regards to smog and other special items, I also got rid of the charcoal canister, but with the smell of gas hanging around the garage, I think I removed to much. At this moment I have the hose from the vent valve just hanging inside the rear right frame. Would it be enough to install the canister at this area and have the hose hooked up, or do you need to have a vacuum attached to it to empty it again? Any other options to look at? Fuel system is all new, including lines, tank, filler tube and hoses, filler cap, so the only one changed is the cannister.

I don't know if it will eventually get full and not absorb more fumes, but it won't hurt to try.

You do need it to be purged otherwise it will eventually fill up with gas fumes and you will be right back to the fume issue.

I have told people for years on emission equipment. PCV system is highly beneficial, EVAP is essentially neutral as far as running goes.

FrazerJames wrote

I actually still have the purge valve - although I have no idea how I’d hook it up now without the original lines hooked up. I bought a new canister so that’s covered at least...

Do you think hooking the purge valve up to the PCV line would get me somewhere?

Does your new canister have this two-port "F" sleeve in it?  If not, you need to get one:



"Port 1" connects to a hard line that goes to your gas tank.  

"Port 2" connected to your carburetor bowl vent, which you no longer have.  But you still need that hose to connect your canister purge valve to.  There should have been a tee in that hose that the canister purge valve connected to.  You can simply use a vacuum cap to cap off the end that originally went to your carburetor.

The other open end of the charcoal canister needs to have a mushroom cap ("4") to allow fresh air in and out.



Here are the connections for the [remote style] canister purge valve your truck should have originally came with:



The "Middle Line From Canister" port is where the canister purge valve connects to a tee that connects it to the charcoal canister at "Port 2."

The "Ported Vacuum" port connects to a [two-port] ported vacuum switch (D3TZ9D473A) that is usually screwed into the heater hose elbow on your intake manifold:



The other end of this ported vacuum switch connects to a ported vacuum source.  This switch is rated at 120 degrees, so it only activates when your engine temperature is above that threshold.  This means your purging will *not* be done on a cold engine or at idle.

The "Manifold Vacuum" port connects to the smaller top port of your PCV valve.  There should be a vacuum restriction (D8TZ9K319A or Dorman 47311) in this hose.


Capiche?

Thanks guys, for suggestions and understandable explanation. For answering the first, I still run a PCV valve at passenger side, connected to the vacuum port at the Edelbrock carburator, with a breather cap on the drivers side.
In regards to the charcoal cannister, I will try and find a place more out of the way, and connect some hoses and vacuum from that position, also would have to run a new stainless line from tank vent through the frame some forward.
Most of the stuff mentioned is still somewhere at the top shelf in the shop, just a matter of connecting the dots.
To be continued......... just want to leave the engine bay as clean as possible.

Coming back to the subject, as I have installed a new 33 gallon plastic gas tank, new filler pipe, hoses and vented gas cap. Why could I not install the vent line from the tank to connection 1 and connect 2 with hoses and small orifice to the air filter, this would draw the vapors back from the cannister and with the small amount of vacuum that is created in this way, the vent cap on the cannister should be enough to equalize this vacuum, preventing to suck fuel from the tank. Where there is still a vented fuel cap, that should open if anything became plugged.
Just a thought to keep things simple.

Andre - I assume you mean to the "clean air" side of the air cleaner.  If so, that might work but there would be very, very little vacuum.  So I'm not sure that would pull many fumes from the canister.  However, I doubt you'd need a restriction.

Having said that, I don't think the vent line is where your fumes in the garage are coming from.  I think it is your vented cap.  These trucks are supposed to have a sealed cap.  So if yours is vented then you have a way for fumes to get into the garage even if you implement the vapor recovery canister.

Why not try a sealed cap for a while and see what happens?  Make sure the vent line is open, or you'll pull a vacuum on the tank and the engine will stop.  But I have sealed caps and an open vent line and I'm not having gas fumes in my shop.

Hi Gary,

Its worth the try. When I got the new filler neck for the gas tank, it came without cap, that's why I bought the one that's on there now.
Next month I know more, when I am back in Holland.