Is my Vapor Cannister doing anything?

[sokoloka]

Tracing the wires in the engine compartment and noticed that my vapor cannister has nothing hooked to it..

As such, I'm inclined to believe it's not doing anything and can be eliminated. If I were to hook it up, how would I?

 

[454Sub]

Its marked on the top in some way shape or form. The line hooked to it now looks like it runs to the tank. Which is correct. The other one hooks to the carb. All it really does is prevent gas smell from leaking out of the tank, and you smelling it, and instead burns it in the combustion process.

And if I had to guess, I would say the smaller of the two unhooked goes to the carb. Thats how my newer one is anyways.

In all, yes it can be removed (depending on emissions) and no performance will be effected. It just prevents you smelling gas fumes around the vehicle.

 

[4xcrazy]

Looks like it's just a carbon filtered vent canister now.

 

[Jessie James]

I was under the impression that the fuel tank & delivery system is a closed system. The vapors that normally leak out are captured in the charcoal canister for a variety of reasons. If those lines are not connected, that may mean that you have disconnected lines coming from your gas tank. I would suspect the slight exposure would mean a tiny loss of gas through evaporation. That's probably no big deal unless you let it sit for months.

However, some newer vehicles will not operate properly because they vacuum seal the gas tank. That's why some new cars won't operate very well if you don't put the gas cap on, or if it is loose.

How does that affect an older truck? I don't know about the K5's, but I did have a 1994 GMC Typhoon with a defective canister and one day the whole truck started reeking of gasoline. The smell was so strong I was pretty sure it would have been a fire hazard had a spark gone off nearby.

Personally, I connect the lines. It's good for the environment and doesn't hurt the truck - if anything it may help you from gas fumes leaking in and causing you to get sick.

 

[dyeager535]

It's a good way to vent the tank. Best way IMO. Should cut down on condensation, cuts down on paint/rust problems (wherever the tank vent is may rust, including a vented cap), and gets rid of that pesky gasoline vapor/flammability problem.

Not a huge fan of the old million miles of vacuum line spaghetti, but before I knew any better, I ran the tank vent line to canister, canister to carb, with no valves, extra switches/hoses, etc. In the case of the one pictured, I suspect the top left fitting was used to control the purge based on engine temp, or timed vacuum port, and likely needs to have vacuum applied for the canister to vent properly.

 

[British Slave]

The hose that is hooked up goes to the fuel tank. The small fitting goes to a tee in the PVC valve hose, and the other vacuum hose goes to the front base of the TBI unit. There is a filter on the bottom of the cannister that needs to be serviced also.

 

[hillbilly deluxe]

I read somewhere that before charcoal cannisters a very high percentage of automobile emissions were simply from evaporating gasoline. Mine's all hooked up. I have a hard time beliving the 40 year old can on my Sub still works, but I never smell gas around it.

 

[livid4dirt]

Maybe they do help with odor, but on both of mine they are removed. The only fuel smell i ever get, is burnt and heading out the tail pipe. No true gas odor at all.

 

[hillbilly deluxe]

Interesting