OK To Vacate Vapor Canister?

[ARCHINSTL]

OK - When I installed the Weber in late '08, I left the vapor canister in situ, but left the electrical connections intact (presumably nonfunctioning) and the tank-to-canister hooked up, but the canister-to-carb line just dangling. No gas smells have been detected under any conditions since.
In the pursuit of under-hood organization, I have removed all of the AC stuff since it was non-functioning anyway. I wonder if the canister can be removed and the line from the tank simply rerouted to the cam cover breather hose leading to the air cleaner? There would not seem to be enough of a vacuum to cause any probs with the tank. It would seem to serve the same purpose by permitting any tank vapors to go into the carb.
I could route the line into the RedLine cleaner, but plumbing into the cam cover breather hose seems simpler.
Any comments on this?
Tom M.

[Petros]

I would not connect it to the cam cover vent tube, that is designed to take vent air both directions, normally the crankcase draws fresh air from the air cleaner, through the crank case, and than draws it into the intake manifold. But as the engine wears crankcase pressure builds and combustion gases will flow into the air cleaner under pressure through both the air inlet and outlet of the vent system. If you connect the fuel tank vent to that system, you could pressurize your fuel tank with crank case vent exhaust. I would not do it that way, find a separate vacuum source for the fuel tank vent.

[ARCHINSTL]

Ahhh-So!
This makes sense to me; I had forgotten that the air flows from the cleaner to the cam cover inside (and with wear, both ways) - D'oh!
But then would it be OK to connect the tank line to a new opening in the cleaner, away from where the breather line connects to the cleaner?
Or - just put a short length of hose on the tank steel line on the firewall - after removing the canister - the short length to prevent any water from entering the line?
I have no idea if the canister has been working, as I've noticed no odors and it sure has not been overflowing/staining the sides.
Thanks!
Tom M.

[splatterdog]

Do not send it to the valve cover. Raw fuel in the crankcase is not good.

I haven't thought about this in a while. I got to the runs real good stage and left it at that. It could be reutilized. Some of the old plumbing needs to go back. Check out the emission section of the FSM, page EC-9. It doesn't specify the T4 but should be similar. You need everything but the outer vent control valve as the weber bowl is vented to the air cleaner(handy if you need to see if your main jets have fallen out). It looks like, by the diagram anyways, that both vacuum sources are manifold. But i believe the vacuum switch should get ported vacuum.

Then you need to check to see if it all still works.

If all else fails, I'm sure Takza could design design an evap carburation system for you.

[sunray]

Do not connect that line directly to ANYTHING on the engine. If you have even a slight backfire it will ignite the fuel vapour in the line and thus the tank. Bad.

Also, if you remove the canister and plug the line you will need some sort of vent system. Check summit racing for something used on a fuel cell. Without a vent and a after plugging the line, there is a chance that when the fuel contracts, you can cause the tank to slowly implode. In my job I have seen this a few times on older metal fuel tank equipped cars. Customer complaint is typically "My fuel tank only takes $7 to fill now. Why?"

[ARCHINSTL]

Thanks to all for the replies.
So - I will just attach a short piece of open hose to the pipe from the tank, as proposed (I did not propose plugging the pipe - sorry if it came across that way).
Tom M.

[takza]

You could just run a tube to the air cleaner...no real vacuum but a place for any vapors to go and be burned. If it's connected outside the filter...not much chance of a backfire doing much.

Tanks are designed to have no air in them these days...and gasoline vapor won't burn or explode...he says hopefully. But with an open tube...when the outside temp drops....air will be pulled into the tank. The OEM canister has check valves in it that mostly prevent this...leave the canister IN and run the tube from it to the air cleaner outside the filter? The line to the old carb could be plugged.

[Neu]

I see no harms in venting it to the air filter...if it backfires I seriously doubt it'd EVER make it's way up a vacuum hose.

And then you use those extra, precious, vapors.

[Petros]

vent it to the aircleaner, pure fuel vapor is not explosive. It is only dangerous when vapor and oxygen is mixed together. YOu can not explode a fuel tank by simply having a backfire into the vent hose. Not likely the flame can travel up such a tiny line even if there was O2 mixed in it.