Hi all,
I have looked at all the threads regarding canister lines, pressure control valves, etc. here’s my dilemma. I swapped a 350 with an Edelbrock 1406 carb into my 85 T/A. I got rid of most of the emissions equipment, a lot of it as it isn’t necessary where I live. I originally had just let my canister vent to the ambient air. However, I’d like to restore some functionality to help alleviate fuel pressure issues. I’m getting a regulator, but I’d like to recycle the gas fumes back into the carb. I have the original pressure control valve hooked up to the canister, and the vent teed into my PCV system. However, I cannot find my purge TVS, canister control valve, or efe TVS. Is it necessary for those to be in place for the system to function properly? Also, the small vacuum line from the pressure control valve, where does it go? Just manifold vacuum? Ported? I will post pictures showing what I have set up and of the line that I’m unsure of. If it’s not necessary to have the smaller vacuum line on the pressure control valve I’ll just remove it.
thanks all,
your friendly neighborhood long haired friend of Jesus

Tank vent to canister, vent from canister to PCV. Note the small vacuum line, does this need to be connected to properly function?

Small vacuum line on pressure control valve, I think it supplies vacuum to prevent operation under warmup/idle?

 

This diagram uses a manual quadrajet carb, but it shows what you need to do with the charcoal canister and related.

 

very helpful diagram! However, I can't find my canister purge tvs or canister control valve unfortunately
-question number one: would it still function properly if I run the line directly to the pcv like I already have and bypass the tvs+control valve? If I understand correctly, the tvs and ccv are for allowing the canister to purge once the engine is at operating temp, and allowing fuel bowl vapors to be recycled. Also, I will add a small filter for the charcoal pieces.

-My car originally had cruise control but my steering column had to be replaced from the previous owner drilling it out and using vice grips to start (I swear it's not hot) so here's my second question: The small line at the Tank Pressure Control valve, do I allow that to vent to air or cap it at the valve? If it sees pressure it will obviously blow a vacuum cap off/leak fumes, but if there's only vacuum I'll cap it.

-Third and final question: there's a line on my cruise module that is the same size as the small one on the tank pressure valve, I can now see that they originally must have been connected, is it a vacuum leak to leave either one open? they are not attached and I do not have cruise on this steering column
I will trace the lines to the magic vacuum ball underneath and see if that plays into the equation.

Thank you for helping me understand what was going on in the mind's of GM engineers in the 80's

 

Q1 - Rock Auto has both items - cheap. Running the vacuum line directly to the canister might create too large a vacuum leak and make the engine idle rough. The other possibility is that you could create a vacuum in the fuel tank, and the fuel pump could not deliver the fuel to the carb. Worst case is that you could actually suck the metal sides of the tank inward - IDK if the word "implode" is accurate here. You are aware of the UFO valve by the drivers side rear tire that works in conjunction with the rest of this fuel venting system? Do a search on this site for UFO valve.

Q2 - The small line to the TPCV is the vacuum source from the carb that controls that valve. If you disable that valve, it will never open.

Q3 - Any vacuum line left open or unused IS a vacuum leak. They need to be capped or plugged.