1978 Charcoal Canister w/o VCV or VSV

[tmckeon]

Hello I have just purchased a 1978 40 series and learned that my EVAP system is 100% not intact (Ignorantly didn't know this was something i needed to look for). Truck smells horrible of gas vapor. Wife is not happy. (common story from my research)
Anyway I have been trying to learn/understand this system and I know I will need a Fuel vapor Separator (I can find used $118) and I know I will need a charcoal canister ($50 vc120 job from amazon), but my question is, is it possible to run this without the VCV and BVSV components? Can you just run the CC out directly to the engine? ( I say engine bc I have no clue where I would need to attach this line out line for vapor to be combusted). I apologize if this is a stupid question. My goal is to get this beauty not smelling like gas so my family can enjoy.
Thank you!

 

[charliemeyer007]

You need to get some books and learn to research by using the online catalogs/

Land Cruiser Factory Service Manuals (FSMs)

Factory service manuals (FSMs) for your Toyota Land Cruiser ! From the 1950s to the present!

www.cruisercult.com

FJ40 and FJ55 Gas tank, sending unit and hoses - 1968-1984 - Specter Off-Road

Toyota Land Cruiser parts since 1983. From the oldest FJ25 and to the newest Land Cruiser, Non USA or domestic 40 Series, 60 Series 80 Series or 100 Series, SOR has the largest selection of top quality new and used OEM and aftermarket Land Cruiser parts in stock in the world. Specializing in...

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[dmaddox]

Welcome, @tmckeon !

I also have a 1978 and have gone over the evap system in great detail, with supporting documentation. Before you purchase anything, it may be helpful to assess what you have (and don't have) and then review my restoration as a resource. Then, put together a plan of attack on how to solve.

Do you have any photos of the inside of your truck behind the passenger seat? The evap hoses, one-way valve, etc? Or, what you do/don't have in the engine bay?

 

[tmckeon]

Welcome, @tmckeon !

I also have a 1978 and have gone over the evap system in great detail, with supporting documentation. Before you purchase anything, it may be helpful to assess what you have (and don't have) and then review my restoration as a resource. Then, put together a plan of attack on how to solve.

Do you have any photos of the inside of your truck behind the passenger seat? The evap hoses, one-way valve, etc? Or, what you do/don't have in the engine bay?

Thank you for your reply. Here’s some pictures showing what I currently have. The tank looks to be the plastic replacement. Out of the tank I have two lines going into the center hole between the front seats, those connect to hard metal lines and then transition back to rubber lines in the engine bay. One goes to a fuel filter and the other connects to the carb I think.
On what should be the vapor side of the tank only one line comes off, not the 3 traditionally, and it goes straight down through a hole and is cut off just below the body (photo of cut line included. I understand this is probably acting as a vent for the tank but I’m almost positive this is the culprit for the gas smell. I also smell a bit of gas from around the hole of the sending unit. Once I get the seat off I will investigate that further.
Ultimately I just want a solution for reducing the gas vapor odor, so I’m open to any and all suggestions. Thanks again!

 

[numby]

You don't really need the BVSV (Brown at the thermostat housing) as it just delays the CC venting function until the vehicle is warmed up. It helps t have it but you don't "need" it imho. If you mean the square Vacuum Switching Valve (VSV) on the fender then no, because the "advance" signal for the VCV is taken ahead of the VSV. If you bypass both of those your tank and canister will vent whenever the advance port in the throat of the carb is exposed - hot engine or no.

What I do think you need is the Outer Vent Control Valve (OVCV) at the canister to control when vapor is available from it to the carb and when the tank is venting to the canister. Then you need the VCV on the fender (next to the VSV) to route the fumes from the canister to the base of the carb when the vacuum is available at the advance port. The second line that seems to be tied into the VSV from the VCV is only a relief line the just needs to go to the little fitting on the '78 air cleaner just above the carburetor.

 

[Rocky_LC]

You also need to see if you can source a steel tank.

Search on plastic gas tank. There are many stories of serious gasoline odors in the cab with them.

I might try that first!

Rocky

 

[dmaddox]

1. Out of the tank I have two lines going into the center hole between the front seats.
2. On what should be the vapor side of the tank only one line comes off, not the 3 traditionally.

1. Yes, that is your send and return to the carb (the send is filtered) You need a gasket in that body hole, I have one I can send you.
2. Yes, seems to just be a single vent line. Those polyethylene (HDPE)? fuel cells are notorious for not making a good seal at the fuel sending unit and expand and contract quite a bit. (no first hand experience). I'm surprised there is just one vent line, which would cause a problem with one of the fuel line check valves.

 

[tmckeon]

You also need to see if you can source a steel tank.

Search on plastic gas tank. There are many stories of serious gasoline odors in the cab with them.

I might try that first!

Rocky

Okay I will definitely look at swapping to the metal 16.5 gal tank. I was bummed when I realized I had this plastic 12gal tank.

 

[tmckeon]

1. Yes, that is your send and return to the carb (the send is filtered) You need a gasket in that body hole, I have one I can send you.
2. Yes, seems to just be a single vent line. Those polyethylene (HDPE)? fuel cells are notorious for not making a good seal at the fuel sending unit and expand and contract quite a bit. (no first hand experience). I'm surprised there is just one vent line, which would cause a problem with one of the fuel line check valves.

This is great info and helps clear up or confirm some of my confusion. I’m in Oklahoma and it’s been in 100°s lately so I’m not surprised that there is some degree of swelling and contraction in that plastic tank.
For now I will look at sourcing/purchase:
-metal gas tank for 1978
-fuel vapor separator
-vapor check valve
-aftermarket charcoal canister
-fuel lines

I know I’ll need more item like the Outer vent control valve and vcv and maybe vsv, but I need to get a better understanding of how all that works. It seems complicated to me. I thought during my research I read of people bypassing the vent/vacuum control stuff and just routing straight to carb or something.

Also I’d appreciate so much that to connect on getting a body hole gasket. If it’s an easily accessible part I can always buy too! Thank you

 

[numby]

Can you just run the CC out directly to the engine?

Just wanted to add that connecting the charcoal canister directly to the engine below the throttle plate would likely result in mimicking a vacuum leak - at least at idle. That's probably why the factory system doesn't allow fumes to be vented until you're well into the throttle.

 

[tmckeon]

Just wanted to add that connecting the charcoal canister directly to the engine below the throttle plate would likely result in mimicking a vacuum leak - at least at idle. That's probably why the factory system doesn't allow fumes to be vented until you're well into the throttle.

Do you think I could just vent the charcoal canister into the air cleaner?

 

[B y r o n]

I know I'm late to the party but maybe the info/diagrams in this thread will help.

 

[zerotreedelta]

There's nothing too crazy about the system - the simplest replacement for the OEM controls would be a basic purge valve like this:

https://www.autozone.com/emission-control-and-exhaust/canister-purge-valve/p/duralast-canister-purge-valve-pv132/91141_0_0

The small port would go to the vacuum signal port above the throttle plate, and the larger port would got to one of the ports on the intake or below the throttle plate. That way you only pull vacuum to the charcoal canister when you're off-idle. Toyota also had a second control that only opened the vacuum once the coolant was at temp - don't have the part # handy, but similar to this:

Amazon.com

 

[Engineer8000]

This is from the 78 2F emissions book. Pretty sure city racer sells the brown BVSV, VCV and white check valve. The outer VCV is energized closed when the ignition is on.

 

[zerotreedelta]

Yup - and the purge valve I linked is basically the generic equivalent of the VCV, and the temp control is the VSV.

 

[numby]

Do you think I could just vent the charcoal canister into the air cleaner?

I think there's a bit of a safety issue with filling your air cleaner with combustable fumes but I honestly don't know how dangerous that would be. You could try teeing into the PCV line which also feeds into the intake manifold below the throttle plate. I have a pre-smog Chevy pickup that did this. The vent from the tank went into a charcoal canister under the hood and then out to the PCV hose. There were no other controls. Everything was unrestricted and free flowing. Seemed to work.

Toyota also had a second control that only opened the vacuum once the coolant was at temp - don't have the part # handy, but similar to this:

Amazon.com

The blue BVSV opens at a slightly different temp than the brown ones. Check the factory emission manual for the actual number. It's probably close enough if you want to run it. I don't think the brown ones used in the diagram posted by @Engineer8000 is available but hopefully someone can confirm.

In the end it's more fun to get the factory system running and then go from there.

 

[tmckeon]

Update:
I got a new metal gas tank and installed it today. Also added a new oem sending unit, and a used fuel vapor separator that I found locally (score!). Got all the new 5/16” fuel lines cut and installed with hose clamps.

Down stream on the vapor side I added an oem check valve, and an aftermarket charcoal canister. (Mounted the CC on a fire extinguisher bracket that the PO had put in the engine bay? Working well for now with some zip ties until I come up with a more permanent solution.

I’m waiting on oem vacuum control valve from city racer and then I will install that and a blue BVSV. (I think I need brown but I will try the blue as suggested above)

Thank you all for your help and input! I really appreciate it.

 

[tmckeon]

So yet again I’ve hit a stopping point and my ignorance is setting in.
I have everything set up and in place up to the charcoal canister, but can’t figure out exactly where to hook up lines coming off the vcv. I have a factory open vcv.
I know a fuel line will go from the purge/vent from the top of CC over to the vcv which I will mount somewhere on the drivers side fender area. From there I know one of the vacuum lines will go to the bvsv and the other to the carburetor. Problem is… I see only one vacuum port on my carb. Is that where it will go? (Photos 1 and 2)
During my research I started to notice my Asain carb doesn’t look like others I’ve seen. I’ll attach photos of what I have. (Photo 3)

So if anyone can’t help me here my questions.
1. VCV vacuum lines go to the bvsv and where exactly on the carb? (with great detail like I’m 5y/o)
2. Where do I screw the bvsv into? (Again, i’m quite a novice when it comes to engines so just saying the name of where it goes will probably not help me)
3. Am I correct in thinking the BVSV vacuum purge goes to the little capped port on the front side of air cleaner? (Photo 4)
4. Probably my biggest issue, where does the other fuel line coming off the vcv go? I’m completely stumped here. (Photo 5)

Sorry for so many questions. It’s just not clear to me and I feel I may not have the carb set up for the evap equipment I’m trying use? If that’s the case can this still work somehow?
Thanks all for any input.

 

[Grayscale]

Wow, there is lots to study, here.
Looks like a non-USA carb, hence the rubber-like spacer between the air cleaner and the top of the carburetor? Also, the plate / insulator between the carburetor and the intake manifold look non-USA-ish. Here is the carburetor identifier: Land Cruiser Carburetor Identifier - Specter Off-Road - https://www.sor.com/cat/042d
I'm under the impression that the BVSV is fitted to the thermostat housing.

 

[Engineer8000]