connecting fuel pump and charcoal canister

[myraley]

Hi guys. Does anyone still have the original charcoal canister set-up? I am still trying to work out previous owner stuff, and I realized he cut all the lines to the standpipe, took out the canister, etc. I am trying to re-create the correct design, so the tank can vent and not rust out, and found a diagram for the gas tank / standpipe section, but I cant find a photo or diagram for how the hoses come together with the fuel pump and the charcoal canister up at the front passenger side. Any photos or drawing would be a great help. Thanks!

 

[bp71k5]

I still have my canistor and the stand pipe all hooked up. I can probably get some pictures.

I think the canister just vents to the air cleaner but I can't be sure since mine was disconnected. I do know there's a single 1/4" hardline from the gas tank area up to the canister. The hardline goes up into that stand pipe eventually.

 

[myraley]

So the 1/4" line goes to the cannister? If that is the case, then that means the middle sized line of the three must be the return, but I thought the return was the 1/4"...
The cannister mounts on the passenger fender, right? I dont know, because mine doesnt have one mounted, but another post here said it mounted to the passenger fender. Not the radiator frame, right?

 

[bp71k5]

I'll try to post the pictures in order so you can see where they go after leaving the vent stack thingy. There's three tubes coming off the stack. Two of them go to vents on the gas tank and the third goes up the passenger side frame rail to the canister.

 

[myraley]

Thanks Brian. I have that part. Can you show me how the charcoal canister is mounted> I looked on mine and I am guessing it mounts on the passenger fender, just behind the radiator frame and forward of the electrical junction box? Am I right?

 

[bp71k5]

Then the hardline above the tank hooks up to the frame rail hardline with a small section of rubber hose.

I have my canister removed so I connected the passenger side vent up to where the charcoal canister line hooked up so I wasn't venting fumes onto the muffler.

If you want to hook it up right, don't do exactly like my picture.

 

[bp71k5]

Then the canister bolts up to the triangular brace between the fender and the radiator support. Right next to the battery tray.

 

[bp71k5]

Sorry, I think I was posting right when you replied. After looking at it, I think the vent line is actually 5/16 and not 1/4 which goes up to the canister. The canister has a little one-way valve on the top that hooks up to the air cleaner.

 

[myraley]

Hey, I called it! That is where I thought it would bolt up! Actually, its not because I'm smart, its because theres nowhere else it could bolt up to... Hey Brian, you and I e-mailed before, havent we? You helped me out with photos before I think.

 

[myraley]

So you only have two lines on top of your charcoal canister? One in and one out? I think mine has three... let me go check.

 

[myraley]

Yep, but fortunately they are labeled "gas tank" "PCV" and "Carb", so I'm good on that. Say, on your fuel pump, is there the line in from the tank and than three lines out on the bottom? I have a line out to the carb, and then two lines that are capped off. I know one should have been a return line, and I can reconnect that, but I can figure out what the other one should have gone to. At first I thought maybe the charcoal cannister, but after looking at the photos you took, I'm thinking that I have the wrong fuel pump.

 

[bp71k5]

Yea, my canister only has two lines. Maybe GM added a third that ties it into the PCV system in later years. The service manual may have a diagram in it.

My fuel pump only had two lines on it. I don't see a reason for a return line on a carb setup used back then.

I actually owe you a seat bracket still in trade for your tach. I keep forgetting about that, but I actually bought some plate that's the right size a while back. Let me see if I can fab one up finally.

 

[myraley]

Thats ok. I would up finding one on ebay, so I'm good, thanks. Although you still may want to fab some up to sell to others on the board who need one. Thanks for the photos. They are really helping me reassemble my fuel system.

 

[thealien]

The canister should have 3 lines. One line goes to the middle line of the three in the vent pipe (the outside two go to the two tank vents). The large line goes to PCV/Vacuum. There should be a small cap in the center of the canister (under the cap should be a spring and rubber valve) this cap has a small vacuum port. This line goes to ported vacuum.

When at idle the canister does nothing. Off idle vacuum opens the valve on the top allowing vacuum to suck the fumes in getting burnt.

 

[bp71k5]

When I was digging around, I ran across my charcoal canister today and discovered why I only have two lines on the top. One broke off! Mystery solved...