Stripping out Emissions Stuff

[AZ79K5Project]

My POS didn't have ANY emission stuff when I bought it. The PO removed everything other than the charcoal canister.

I had to replace everything to register it. The maze isn't that bad once you start.

It ran better with everything hooked back up.

 

[buffblazer]

charcol canister

not to highjack but i removed all my emissions along time ago and left the canister hooked up to the tank. but nothing flowing into the canister. yall talked about tank venting i just removed the canister yesterday, will that affect the venting?

 

[bp71k5]

i just removed the canister yesterday, will that affect the venting?

If the line isn't plugged, it'll still vent ok right into your engine compartment.

 

[vortec]

i've said this before with regards to inspections; make the stuff look right (in other words just have it there) run about 1/3 e85 2/3 e10, and you'll fly through inspection with no problems. i've passed twice that way with almost no emissions equipment. now, it's old enough to be exempt.

 

[Kenny78]

Im still interested as to which vac. signal the can goes to. I plan on reconnecting mine but the diagram does no good since I have an edelbrock.
Thanks,
Ken

 

[myraley]

Kenny, according to the canister I have, one line comes from the gas tank, and two lines come out. One goes to the PCV valve, but it could also go to manifold vacuum, because that is what the PCV valve gets. The other line goes to "carb", but should go to ported vacuum, according to the diagram I found in a book covering 67' to 77. If anyone has an emissions diagram for a 1975 454 engine, I would love to see it, because thats what I have swapped in, so all the stuff I have on 67-72 isnt helping me much.

 

[Kenny78]

I appreciate it MYRALEY, I guess Ill have to study it further because I was hoping I could just run one ported vac. line. Have to google to see why you need both.
Thanks
Kenny

 

[myraley]

On the diagram in Chilton's (and I think Haynes too), it shows the "carb" line going to ported vacuum because that line opens up (against a spring)the PCV line when there is vacuum. I believe the idea is that at idle, the PCV line is "capped" and engine will not draw any vapor from the PCV line, but as the ported vacuum increases, the "cap" is pulled up and will draw more through the PCV line as the vehicle accelerates. My initial confusion, and maybe yours too, was that I thought vapors were going through BOTH the carb and the PCV line. No, the carb line simply uses vacuum to OPEN the PCV line as you accelerate. Sorry, if I could scan it I would and it would be a lot easier to understand.

 

[AZ79K5Project]

On the diagram in Chilton's (and I think Haynes too), it shows the "carb" line going to ported vacuum because that line opens up (against a spring)the PCV line when there is vacuum. ...

This what you are looking for? (This is from Chiltons):

 

[myraley]

Hey! Thats it! very nice, and just about the way mine is connected now (I dont have TVS, or TCV, or whatever that is). Thanks!

 

[buffblazer]

This what you are looking for? (This is from Chiltons):
View attachment 66104

on the line that goes to the tank what i use to plug it off but still let it vent i figured if i leve the hose off its just gonna get filled with mud and water

 

[dyeager535]

Problem is there is really nothing out there that will stop water/moisture from getting back to the tank with the vent "open". People have used little filters (such as for fuel) or simply used one of the axle breather vents.

 

[AZ79K5Project]

I'm going to throw this out there - How much gas evaporates through an open vent line?

If you have a 5 gallon jug of gas in the shed with the same sized line - would it evaporate pretty quickly?

What about if it were plumbed through a device like the factory canister that is used for emissions? Is a factory canister valved or constructed to prevent evaporation or excessive evaporation? I have no idea - just wondering.

 

[dyeager535]

I'm not exactly sure why EVAP was considered necessary, I wasn't around prior to it's introduction, maybe large parking lots in CA were pretty bad before?

It's obvious it doesn't evaporate off *really* quick with an open vent, but I suppose in keeping out as much air as possible, you help prolong the life of the fuel if it sits.