73-87chevytrucks.com
General Site Info => General Discussion => Topic started by: Maintenanceman on February 20, 2009, 08:31:40 pm
-
Im changing my carb and intake set up and I stumbled across a component that I wasnt sure what it was. If you look down beside the radiator on the drivers side, theres a coffe can size canister down there. It has a vacuum line that ran to my qaudrajet but the new edelbrock doesnt have a vacuum port for it. I thought it was something to do with the EGR or emissions components. Is this correct? Do I actually need this thing to run? By the way all of the EGR components that were on my truck (werent hooked up) but are now gone. Sorry I dont have any pictures of the part I was looking at but Im at work and was just curious.
Truck info is in sig.
TIA,
Ben
-
Fuel tank vacuum canister. It draws fuel tank vapors into the carb. It will run with out it.
-
Is it a neccesity?
-
I'd leave it on.
-
So can I just tie it into a vacuum line somewhere?
-
There should be a diagram on the top of the core support, it will tell you how to route the vacuum lines.
-
What exactly does the cannister do?
-
It directs the gas fumes into the carb to be used. Instead of letting them into the atmosphere.
-
On my '85 there was also a line that pulled excess vapors from the carb fuel bowl. I now have an Edelbrock carb as well and it doesn't have any accommodations for such a line so I have it plugged at the vapor canister. I'll post pics of how I have mine hooked up tomorrow if you like.
-
Hook it to the breather inlet of your air cleaner. Do not hook it to a vacuum source.
-
Thanks guys thats I was looking for.
-
What kind of air cleaner do you have?
-
my motor book shows that since you have removed everything else, one line goes to the tank, and the line to the engine goes to the port vaccum line. its the port on the front of the edelbrock that pulls NO vaccum at idle. There should be a thermostatic switch in between the canister and the carb. Stock, one line went to the carb to the ported vaccum port, and one line tied in with the pcv hose or went to the egr valve.
-
Hook it to the breather inlet of your air cleaner. Do not hook it to a vacuum source.
What do you mean? On mine there is a breather line (that goes to air cleaner), a inlet line (from gas tanks), a purge valve line (to thermostatic valve, then ported vacuum source), and a purge line (to full vacuum, tee'd in with PCV). This isn't right?
-
I have an Edelbrock Intake that I bought at autozone. There is no place to hook it into.
-
You don't want to have it go from the Charcoal canister to a vacuum source. The purge valve will direct it into the intake via either the vent or a TEE. A vacuum line directly to the cannister purge would cause the cannister to flood.
If you have an aftermarket air cleaner on the base you may have a capped vent which you could use. Just be aware a backfire could cause an explosion if a check valve isn't used.
-
Vile: Because there are several different styles of canisters and because I'm a little dense, I'd like you to look at the way I have it hooked up. You are saying the the purge line I have tee'd in with PCV should be vented to the air cleaner. I would think the vent to the right would prevent vacuum from pulling liquid fuel into the canister. No? Based on the pics I took before pulling apart my 305, this is how it was hooked up originally (except the vent was going to the air cleaner).
(http://i208.photobucket.com/albums/bb247/1985C10/canister.jpg)
This is the go-by I used:
(http://i208.photobucket.com/albums/bb247/1985C10/EVAPsystemdiagram01.gif)
-
I just took mine right out. Its a cleaner look and it makes for a perfect work bench decoration... :P