Hooking up Charcoal canister and fuel seperater (1 Viewer)

[calsum2]

The PO removed all the smog equipment including the charcoal cannister and fuel separater. Carb was swapped out for a weber.

The fule tank is capped with rubber caps that disentagrate every year. I am tired of the gas in the cab and the expansion and contraction of the gas tank.

I have purchased the fuel seperater and charcoal canister along with brackets. I know that the canister mounts on the frame across from the dizzy. But don't know how to plumb it back to the gas tank properly. Nor do I know how the fuel seperater is to be plumbed.

Can anyone assit?

In regards to hoses what type and size hoses do I need to phurchase? How many what lengths? Also If I remember there may also be 1 or 2 hard lines that run between the sepater and canister?

Any help is appreciated!!

 

[FJ40V8]

im in a similar boat, got a chev, no carbon canister, return line is plumbed into what would be the carbon canister line, it isnt good need to sort it out!

 

[mossman40]

Calsum2,

It will help if you mention what year 40 you are talking about. Here is a picture of the seperator:

One of the vendors on here sells a "hose" kit that should help. Not sure if it is SOR or CCOT..........but the hose is available at your neighborhood parts store and you just cut it to length. I can't remember if it is 5/8 inch or not.

 

[calsum2]

Thanks for the reply! I have a 76 fj40. I assume that the three lines from the separator are to be hooked into the three lines that come out of the tank n ext to the fuel filler.

The single port goes to a hard line that runs along the frame to the engine compartment to the charcoal canister?

On top of the charcoal canister there are three nipples on the top and one hose that comes out the bottom. I assume that the line from the fuel Separator goes to one of the three nipples on the top of the charcoal canister? Does it matter which one?

What is the purpose of the two remaining niples on the top of the canister and the one on the bottom?

Again I have a Weber carb that has been desmoged

 

[desertpat]

Separator Plumbing

Calsum2,
I attach a pic from a parts manual for non-USA 1980 and up that might help. As you can see, some FJ configurations do not use the cannister.

On one of my late 40's, the cannister is mounted to an angled adaptor bracket, and that bracket mounts to the ladies side fender, below the battery box inside the engine compartment.
The bottom cannister port goes to a 7" or so long hose, then to a metal tube. The tube is open ended and dumps into a hole very near the the forward tub body mount - on the ladies side.
There's a hole in the side of the "tub mount member" that it just empties into.
The extra upper port on the cannister goes to some engine component for fumes - maybe. I just put a longish hose on that port so it flops over and water doesn't get in the cannister.

I have 2 late model 40's and 1 doesn't have the cannister.
Never had the gas smell problem on either '40.
The 40 without the cannister used to pressure up in the fuel tank .... pressure or vacuum ?? and would hiss when I removed the gas tank cap.
I blew compressed air into each of the 3 hoses that go to the fuel tank ..... and that stopped the hissing immediately. Can't say for sure cause I haven't filled it up much or driven it much since .... it's now in Canada.

Don't know the function of those 3 hoses going back to the tank, but I suggest to make sure they are clear by compressed air - this may be related to the gas smell???
Let us know what you find and good luck.
cheers

 

[ingomar]

My '78 is set up as DesertPat describes. I use a sealed cap, it stops the smell. As long as the hidden vent (the one that goes under down inside the body tub brace) is open and working I don't think it'll give you any trouble. My tank stays at basically atmospheric pressure, even with a sealed cap.
I have a V-8; it's been a long time and I don't remember any line going to the motor compartment. I do know I don't run one. Just make sure it vents.

 

[calsum2]

Thanks guys this the helps.

Can anyone comment or post pics of thier Charcoal canister and identify where each of three hoses that come out of the charcoal canister are routed to on a properly desmoged 2f with a weber carb. Also where should the hose at the bottom of the cansister be routed?

 

[calsum2]

Anyone else have some advice?

 

[mossman40]

calsum2,

You are correct on the seperator hookups. I found this in a search and posting it in hopes it will help some.

 

[desertpat]

Lines to tank

I was hoping someone would explain the function of the 3 hoses that route to the gas tank from the separator.
A roll over provision comes to mind .... but I might have been hallucinating at that time.

 

[numby]

I don't know 76 hose routing so this is based on later (78) stuff. If you have three tubes on top of your canister then read on. At least you'll have a better idea what the tubes run to. There is also the fourth line from the bottom of the canister which dead ends inside the tub support under the passenger side floorboard. This is basically a drain in case of overflow but also can be considered an air source if the canister is under vacuum and other lines are blocked.

The largest tube (on top of the canister) passes through the Outer Vent Control Valve and then to the float bowl on a factory carb for collecting float bowl vapors when the vehicle engine is off. There is no check valve at that opening thus the Outer VCV controls flow from the carb and requires current (start/run) to close. You probably have no way of using this tube with your Weber.

The other two tubes are labeled. The "TO TANK" tube is the single line from the collector that is inside the cab behind the passenger seat. This is the right hand tube that seems to go nowhere in mossman40's diagram. Gas vapors are collected from the fuel tank in the collector via the three hoses. When there is enough pressure the "TO TANK" check valve will open to allow fumes to be collected in the canister. This is a passive action. Blow into it to make certain it's still functional.

The "PURGE" tube is what routes the collected fumes from the canister to the intake manifold (actually the carb base plate) at the appropriate time via the functioning of the computer and Vacuum Switching Valve - if you have one. I don't see one in the diagram posted by mossman40. I don't know if it's correct for your year. In the diagram (middle tube) this seems to be controlled by using vacuum from the EGR port to open a dedicated VCV and allow the fumes to be sucked into the manifold below the butterflies. There is a small BVSV (usually located in the thermostat housing) to prevent this from happening until the engine has reached a pre-set temperature. This tube has a check valve as well. It needs to vent outward. Blow into one of the other tubes while blocking those remaining. Air should flow from the "PURGE" tube to be functional.

DISCLAIMER: PLease follow the advice below at your own risk. I make no claims of expertise or appropriate use. All the following assumes you have no factory emission equipment other than the canister.

Here's what i would do....

Option 1 - Run the line from your tank to the "TO TANK" port. Cap the "PURGE" port. Run the large port (OVCV) in a loop up and then down and as far to the rear of the vehicle as possible. Avoid any possible sources of ignition. Run the line underneath as described above. This acts as an open vent line for evaporating fumes from the canister (which might condense) to the rear of the vehicle to help you avoid smelling anything in the cab.

Option 2 - Run the line from your tank to the "TO TANK" port. Cap the large OVCV port. Run a line from the "PURGE" port to manifold vacuum. If possible use the correct VCV and BVSV so that the system is not always on.

Option 3 - Any combination of the above that you deem safe and effective. You mostly need to collect fumes from the fuel tank in the canister and then route them at the appropriate time to the intake manifold.

Option 4 (for V8 owners) - I had an old SBC truck that ran the Chevrolet factory "PURGE" port to a T fitting at the PCV valve. Seemed to work well.

Whew! HTH.

 

[Fast Eddy]

Option 2 - Run the line from your tank to the "TO TANK" port. Cap the large OVCV port. Run a line from the "PURGE" port to manifold vacuum. If possible use the correct VCV and BVSV so that the system is not always on.

I like option 2. You probably have a BVSV already blocking a hole in the thermostat housing.

The three lines from the tank to the collector are because there are three chambers separated by two baffles in the tank. (Pretty sure.)

 

[calsum2]

Numby thanks for the detailed and well thought out reply. This helps alot. I have a few question for you that I will write up later....for now I have to help my wife put the kiddies to bed.....or I will get the look

Bye the way I just finished reading your advice and started blowing into the charcoal canister to test the valves. 3 year old daughter walks up and asks...daddy what are you doing. At that moment I thought to myself oh boy how am I going to explain this one. I kept it simple and told her that it is used to catch burps from the gas tank in daddies truck. I think she in away gets it. To funny...she just might make a good member of my pit crew in a couple of years.

 

[Dingadong]

Can someone chime in on this style canister, with only 2 ports up top. Getting ready to hook it up to my sbc, Im having to put in all new lines and dont have anything existing to go by. None of the ports are marked on the canister, and I have searched but cant find an answer. My 40 is a 76 and uses this type of vapor separator.

Im guessing that the line with the check valve from the vapor separator goes to the bottom port, circled in yellow.

Here is what I think I know, but not sure. One of the top ports should either run to the carb or to the air cleaner, to pull the vapors in on start. Im not sure my edelbrock carb has a port for a line, will have to look when I get home. If it does not, Im assuming running a line to the air cleaner somehow may be sufficient.

My carb does not have a fuel return line. Should this port on the gas tank be capped, or can I run another line from the canister back to the tank?

Any advice would be appreciated.

 

[Biscuit]

The way I have my charcoal canister set up for a carb with no return line is as follows:

Top port 1: Fuel tank breather
Top port 2: Behind air cleaner before carb (stock F intake has this, but should be easy to plumb to any air cleaner assembly)
Bottom port: Fuel tank return

This way any vapors while parked go into the canister, and if they condense into fuel they will make their way back to the tank. While running the vacuum pulling through the carb will cause vapors to be sucked into the carb as part of the air and get burned in the engine.

Not this is different from stock where the bottom port would drain into a rail below the tub (i.e. onto the ground)

 

[Dingadong]

Sweet, thanks for the info and quick reply. Im was also assuming that it doesnt really matter which top port ran where, but Ive never opened a canister up to see how it is plumbed inside. Thanks again.

 

[cmiller114]

While you're plumbing, keep in mind motors sometimes backfire through the carb. Don't turn your cruiser into a IED.

 

[Dingadong]

.....

Yeah, but isnt this is the way cars came from the factory on many many makes and models, no? Many of the aftermarket carbs available have a provision for a vaccuum line to the canister. Is this a realistic concern? What about setups that utilize a return line from the carb directly to the fuel tank... I guess that line would have liquid vs vapor, but still could be a concern, no?

I suppose that you could install a one way valve, similar what is present on the line from the vapor separator to the canister. Might prevent vapor flow back to the canister in case of a backfire ? ....

 

[Rocky_LC]

The truck might vbackfire through the carb, but the vent line is attached throuh the float bowl vent.

I doubt if this fills with flame - I think you are pretty safe.

Rocky

 

[bdhelpaso]

The PO removed all the smog equipment including the charcoal cannister and fuel separater. Carb was swapped out for a weber.

The fule tank is capped with rubber caps that disentagrate every year. I am tired of the gas in the cab and the expansion and contraction of the gas tank.

I have purchased the fuel seperater and charcoal canister along with brackets. I know that the canister mounts on the frame across from the dizzy. But don't know how to plumb it back to the gas tank properly. Nor do I know how the fuel seperater is to be plumbed.

Can anyone assit?

In regards to hoses what type and size hoses do I need to phurchase? How many what lengths? Also If I remember there may also be 1 or 2 hard lines that run between the sepater and canister?

Any help is appreciated!!

How did you end up setting yours up? I have the same issue and still haven't figured it out.