Fuel overflowing into EVAP charcoal canister

[realpank]

Still trying to get my 1987 325 MH home from Florida.

Latest alternator breakdown left me in Montgomery, AL.

As I was ready to pick it up when the mechanic informed me that gas was flowing into the charcoal canister and eventually overflowing from there!

A new carb and gas tank were installed in FLA as they had been fouled. It had been run briefly with dirty fuel so I'm thinking that there is still particulate in the carb. I ran the unit for at least five hours from FLA to AL and is ran fine.

Mechanic said he could crimp line to canister to stop the flow but I said that does not stop the root cause. He said may have to install another carb ($$$!!!!) I am going to request a carb clean/rebuild.

Anyone come across anything like this.

Thanks in advance for your replies.
Chris

[Zil]

I think you are right. There is dirt in the carb. Holding the float valve open. If you find someone as old as me, they can carefully disassemble the top of the carb and clean it enough to get you home. You will have to replace the canister.

[Hans 34.5]

On my 34.5.

There is a return line to the tank I think it is a 1/4 line is it hock up wrong maybe.
You talking about the canister in the right front wheel well. I have my fuel tank out and right front wheel off to change a bad brake line. Tell me where is your fuel canister.
Also when I pulled my tank down one of the fuel lines that goes to the Gen set was pinched on the frame cross member and the tank. There is like 5 lines on the tank if I remember. One is a return line.
And you could have a fuel filter and electric fuel pump just in front of the tank.

[realpank]

Thanks Guys,

I recon the mechanic will look at cleaning the carb first and see how it runs then. I am hopeful this will fix.

Hans, I am not with the unit and it is new to me so I don't know location.

Cheers

[dannydimitt]

if the engine starts and runs OK with fuel coming out of the canister , the carb is just fine , if the float was sticking open , the engine would flood , with lots of raw gas getting into the intake manifold . The gas could be from the evap line from the fuel tank , if the tank is completely full , the expansion of the fuel when it gets hot could be forcing liquid gasoline into the evap line that runs to the canister . but not being there to see the beast limits any sort of proper diagnosis . One more item to consider is if whoever hooked the hoses to the new tank got them crossed ?
take the gas cap off or loosen it and see if the canister stops leaking gas .

[realpank]

Thanks Danny,

Good points, my sentiments on trying to diagnose from a distance.

Tank was not full when they tested it(to my knowledge), would it still run ok with the lines crossed? I ran it for about 5 hours before the electrical failure and it ran fine.

[ROBERT CROSS]

"new carb & gas Tank".....it runs well, that leaves the gas tank.
Lines may be pinched, or not connected properly.
1987...old tank was rusty?, carb gunked up.

All guesses except, Ethanol=all new lines.

Bob

[J. Morgan]

Originally Posted by dannydimitt

if the engine starts and runs OK with fuel coming out of the canister , the carb is just fine , if the float was sticking open , the engine would flood , with lots of raw gas getting into the intake manifold . The gas could be from the evap line from the fuel tank , if the tank is completely full , the expansion of the fuel when it gets hot could be forcing liquid gasoline into the evap line that runs to the canister . but not being there to see the beast limits any sort of proper diagnosis . One more item to consider is if whoever hooked the hoses to the new tank got them crossed ?
take the gas cap off or loosen it and see if the canister stops leaking gas .

Yep.... What Danny said...

[TomKirk]

Convert to Edelbrock carburetor. You'll be glad you did.

Tom

[Waipio Rim]

Originally Posted by TomKirk

Convert to Edelbrock carburetor. You'll be glad you did.

Tom

Which one, 600 or 750 CFM? Why is it better?

[dannydimitt]

Originally Posted by dannydimitt

if the engine starts and runs OK with fuel coming out of the canister , the carb is just fine , if the float was sticking open , the engine would flood , with lots of raw gas getting into the intake manifold . The gas could be from the evap line from the fuel tank , if the tank is completely full , the expansion of the fuel when it gets hot could be forcing liquid gasoline into the evap line that runs to the canister . but not being there to see the beast limits any sort of proper diagnosis . One more item to consider is if whoever hooked the hoses to the new tank got them crossed ?
take the gas cap off or loosen it and see if the canister stops leaking gas .

Just thought of one other thing , if they put a new unvented gas cap on a tank that is supposed to have a vented one , it might cause this problem with a full tank when the fuel expands.

[bkahler]

Originally Posted by Waipio Rim

Which one, 600 or 750 CFM? Why is it better?

I bought an Edelbrock 1406 which is a 600 CFM unit along with a Performer 2161 intake manifold.

Now if only I could take it for a test drive!

Someday...

[TomKirk]

Originally Posted by Waipio Rim

Which one, 600 or 750 CFM? Why is it better?

It's all about simplicity, my friend. Edlebrock is the new Carter AFB (aluminum four barrel).

Once I ditched the Quadrajet, my Suburban thanked me for it. I kept the cast iron manifold. For longevity, I never did like aluminum.

As for CFM, engine size makes a difference. You also hafta keep in mind that you're driving a motorhome, not a dragster.

Contact a speed shop in your area. Tell them what you want in the way of performance, reliability, and common sense. Around here, it's Jim Green's in Monroe, WA.

Jim Green

Tom

[Gregsch]

If you have the original mechanical fuel pump it pumps fuel to the carb and what ever excess fuel the carb does not require is deverted thru a return line back to the tank. Maybe the lines are not hooked up properly and the excess fuel is being deverted to the vapor canister instead. Could be that the excess fuel filled the canister then was pushed back to the tank thru the line that was designed to return vapors to the tank. Also could be that at highway speeds you are using enough fuel that it really isn't a problem. Only at idle the pump would pump way more fuel than you need. Sounds like a simply hose problem to me. I would not mess with the carb until all other causes were eliminated. Very likely your Q-jet is just fine.

[realpank]

Thanks for all the replies,

Mechanic who installed gas tank had lines switched!!

Drove home 20 hours...no fuel issues (besides buying lots of it)

Cheers

[dannydimitt]

Originally Posted by realpank

Thanks for all the replies,

Mechanic who installed gas tank had lines switched!!

Drove home 20 hours...no fuel issues (besides buying lots of it)

Cheers

Glad ya made it home OK !