So, I did all this crap in one extended shot (it's not truly done yet, the canister itself and the vapor lines need to be ripped out, but this is what it takes to get the car running right after doing all this...). Car is a 1985 4+3.

The intent of this mod is as follows:
1. Delete as many possible sources of vacuum leaks as you can.
2. Stop any problems associated cannister from creeping up. If it ain't there, it can't break and screw something else up. I've heard of the charcoal itself finding its way into vacuum lines and screwing other stuff up. Not here. Not this car.
3. Eliminate the weight of the system and clear space under the hood as much as possible. Someday, there are two turbos going in this car, and I'm going to need all the room I can get.
4. Do all of the above without making the car or the garage stink.

NOTE: If you follow this How To as shown here in the first post, you can still really easily undo this mod. After what is shown here, the canister gets ripped out along with the solenoid associated with it and all the extraneous and now useless tubing. I'll write up how I do that at a later date.

From the top:

This is a standard $9, aftermarket replacement gas cap available virtually anywhere, shown disassembled. It actually is vented (even though peeps will claim it's not...), it just isn't vented straight to atmosphere like the old days. In the cap there are two valves, a black tiny poppet valve and a larger white valve the poppet valve seats in.




1. If the pressure inside the tank is high, the black poppet valve opens and vents the excess pressure to atmosphere.
2. If the pressure inside the tank is low, the white valve opens and atmosphere enters the tank.

So, there are two ways to approach this... either modify the black poppet valve spring or remove the black poppet valve entirely. I got rid of it entirely. If you are worried about you getting in an accident and your car rolling over and gas leaking out and igniting and BBQ'ing you DON'T DO THIS MOD AT ALL:



Now to reassemble:






Now that that's done, install it and keep your old gas cap, just in case.

Ok, to the engine compartment now...

This is my 1985 before any of this... note the two vacuum lines running right behind the alternator. One of them goes to the throttle body, the other goes to a bracket hidden under the black cover over the fuel injectors...



Pull that cover, and underneath you will find the wiring for the injectors and this bracket:



For my car, I pulled the cover and the bracket. I was installing new, temporary chrome valve covers ($26 new, delivered from Spectre Performance on Ebay) at the same time so I can refinish my stock ones, so getting rid of it was easy. If you're NOT doing that, pull the vacuum line to the canister off and cap the tube. If you are pulling it, you will need some 3/8" hose (from the PCV) and some 1/2" hose (to the plenum) and an adaptor between them and you get this:



Please pardon the Bubba Brass fittings... they were available and 3/8" to 1/2" adaptors are hard to find. I have a 10 pack of them coming from Amazon... so... uhhhh… that's use one and 9 spares, just in case...

Finally, remove the vacuum line you just disconnected from the tube shared with the PCV and cap it off. I put a hose clamp on it just for giggles as a temporary "just in case" until I finish ripping the rest of this worthless garbage out...




There you go.

In part 2, I'll detail everything else that can be removed from the car and how to do it.

In the meantime, Lump (Child Rottweiler of DOOM) will be busy busy trashing my garage:

 

Hey man, I know this thread is a little old. But did you ever end up deleting the rest of the evap system? I'm in the middle of ditching mine on my 85 and wanted to know if you ended up removing the metal line to the tank along with the purge canister and the cluster of lines and check valves. Thanks, hope all is well.
-Cody