Raw Gas Smell in and out of 1978 FJ40

[bdhelpaso]

This vehicle has no remaining emission controls other than the vapor separator and the charcoal canister. In the past, I have replaced everything but the charcoal canister....lines and all. Still a smell. Today, a mechanic told me to cap the 3 vapor lines coming out of the top of the tank. The return line on the side of the tank is capped as well. He said there should only be the line from the top of the tank to the filler neck and the line to the fuel pump and to make sure I had a vented gas cap. Not sure if this really works or if I'm setting my self up for some problems. He said to pull out the vapor separator and charcoal canister that they are not needed since I got rid of all of my emission controls. Please help and advise.

 

[Solace in Solitude]

He's wrong - the evapo and canister, when properly connected prevent gas fumes in the cab... Assuming your tank doesn't leak.

Here's a link to a thread, with a '78 de smog schematic

What he's suggesting would vent gas fumes to the environment.

 

[Curt]

Going down the easy road here. have you looked at all your fuel lines and checked to see your fuel tank isnt leaking?

 

[SouthBostonFJ40]

I'm confused, are the three vent lines on top of the tank hooked up or are they open?

 

[Solace in Solitude]

I read it as him I implying they are hooked up and his mechanic suggesting they be capped...

 

[78fj40mg]

I agree with @pngunme !

What your mechanic has recommended to you is an explosive solution! There's a major purpose for all the hoses in venting your fuel tank that Toyota designed for this vehicle. The intent was to safely vent the explosive fumes and recirculate them back to the carb and intake manifold and ignite into power rather than discharging them to the atmosphere and endangering the vehicle occupants and the air we breathe. Gas fumes are volatile and will ignite with static electricity and other ignition sources, i.e. cigarettes, etc., specially when filling your tank with gas. If you value your life Don't do it!

Follow the schematic

 

[sggoat]

Agree w/pngunme, and 78FJ40mg--Are you absolutely sure your fuel tank is intact?--tiny pinholes can develop underneath-not enough to see drips on the ground-the gas evaporates before it gets that bad, but it sure does smell bad.(mine looked like a pincushion when I finally found the problem--

 

[Rocky_LC]

I've had one of the three tubes on the (cheap plastic) vapor separator crack - my truck stunk for a while until I found the issue...

Rocky

 

[78fj40mg]

Welcome to the MUD family!!

 

[bdhelpaso]

He's wrong - the evapo and canister, when properly connected prevent gas fumes in the cab... Assuming your tank doesn't leak.

Here's a link to a thread, with a '78 de smog schematic

What he's suggesting would vent gas fumes to the environment.

I have a new tank. The problem is that I have a weber carb. See the attached diagram. Is this the proper way to hook it up and I need an answer to B and C on the diagram

 

[bdhelpaso]

Is this the way to hook up a weber carb

 

[Solace in Solitude]

I'm not familiar with Webers... But, that looks fine for hooking up a carb that doesn't use a return line.

On your diagram, B routes back into the cab (down low) and ultimately IIRC, vents to atmosphere. C : I can't recall a check valve there and I can't get to my 40 to check... Maybe Mike (@78fj40mg) will chime in.

But, my canister has three ports on top... Like the picture I linked, above, and the picture Mike posted above.

BTW there is a purge procedure for the canister in the emissions manual... You can see it in THIS LINK

 

[bdhelpaso]

I'm not familiar with Webers... But, that looks fine for hooking up a carb that doesn't use a return line.

On your diagram, B routes back into the cab (down low) and ultimately IIRC, vents to atmosphere. C : I can't recall a check valve there and I can't get to my 40 to check... Maybe Mike (@78fj40mg) will chime in.

But, my canister has three ports on top... Like the picture I linked, above, and the picture Mike posted above.

BTW there is a purge procedure for the canister in the emissions manual... You can see it in THIS LINK

I definitely need to replace the charcoal canister. Best place to get a quality used one?

 

[Solace in Solitude]

Maybe Georg in Stockton @orangefj45 here on MUD.

Some have replaced theirs with new aftermarket canister - THIS THREAD talks about an aftermarket... I know nothing...

 

[78fj40mg]

It would be helpful if you can post some pics of your carb depicting all the suction ports.

 

[batcon]

Check the fuel sending unit bolts and make sure they're tightened properly.

 

[bdhelpaso]

 

[bdhelpaso]

It would be helpful if you can post some pics of your carb depicting all the suction ports.

see pictures I posted

 

[78fj40mg]

Those pics are good but not of your carb = carburetor.

 

[78fj40mg]

The green hose from the outer vent control valve goes to your carb/intake nipple (the charcoal canister has three top connections and one on bottom)(follow the green)

The red hose goes to the VCV valve

The yellow hose comes from gas tank

And routes across the back side of engine(follow the green hose)

Along the drivers side under the brake master cylinder(follow the green hose)

And connects to the intake manifold nipple (follow the green hose )

(follow the green hose)