Pig Specific Desmog and Charcoal Canister (1 Viewer)

[wngrog]

Lots of threads out there about desmog but I can not find my specific question with a title search. I'm sure it's covered but buried in other threads.

If so please link here to help people searching

My question.

I've removed the smog garbage from the 1977 2F in my Parts-O-Pig project.

The remaining stuff is attached to the charcoal canister which is also about fuel evaporation

What do I do with this stuff? Keep it? Does any of it need vacuum?

At this point I just unplugged it and looped all the hoses back to themselves.

I'm installing a non US desmog carb and all it needs is one line from distributor

 

[PabloCruise]

Unless you like the smell of raw gasoline in the summer, yes, you should keep it.

That looks like a switching valve the can is hooked up to. If you think it still switches on and off ala some sort of emissions computer, hook the other port on the switching valve to some sort of vacuum source.

Make sure the tank can still vent to the charcoal can. Make sure the one-way valve near the evaporator in the DS quarter panel has not split. otherwise you will get that raw gas smell...

 

[wngrog]

So far with a full tank I got no smells.

What does the charcoal canister go to on pre emission Pigs? I definitely want it and the evaporator stuff in the fender. I was just wondering about the switch device.

I've got no reason to think it does not still work. All the other electronics are coming to life.

 

[LAMBCRUSHER]

ok the solenoid shuts the line OUT of the canister and is controlled by the ignition; ig, ON = open valve...

the thing dumps into the intake stream before the plate IIRC, so it just needs to get back to the air cleaner housing, really.

the idea is; engine on, gas vapors are drawn into the intake; engine off, valve shut so you don't smell gas...keep it. blow thru the canister to make sure it flows. it can be cut open and filled with fish tank carbon...

 

[wngrog]

The two are separate with both having their own pigtails. Do they flow in line?

 

[LAMBCRUSHER]

Hmmm. okay you've got federal smog...check out the desmog threads in the 40 section...my cali rig had a big multi channnel vacuum valve and followed a different hose routing...there should only be one valve between the carb/ air cleaner/intake area and the charcoal can...I want to say that 3 port valve is for the evap, but cannot remember why it has 3 lines...sorry.

 

[onemanarmy]

I've removed all of my smog stuff too.

Leave the charcoal canister just as you have it now, with the line coming in from the firewall, and then have a small vacuum pull on the 'exit' port closer to the front of the vehicle.

Those switching valves are obviously not doing anything now (one seems to be unplugged) and once all the other smog components are removed, (even if you have kept the computer) you have broken the 'vacuum' chain, so they are moot.

 

[wngrog]

Great info. Thank you.