Raw fuel Leaking From Carbon Cannister

[2-4-0]

So today driving I noticed my car sputtering etc.

Popped the hood and noticed raw Fuel leaking from the bottom of my Carbon Cannister.

I disconnected the 2 vaccum lines from the canister that go to the throttle body and the sputtering went away. but there still is a drip from the bottom of the canister

What would cause this and how do I fix it?

Car is a 93' S13 w/ SR20

Thanks
-Ben

[2-4-0]

Any ideas? Anyone?

[n240sxfnatic]

remove it and seal it off at the tank

[g6civcx]

It's like every other day we get a thread like this. Read carefully.

Never ever seal off the fuel tank vent line. Pressure buildup = explosion = fire.

In order for the evap charcoal canister to work correctly, you need the evap solenoid. Most likely your SR didn't come with it. That's why the fuel is leaking out of the canister.

Fuel is building up in the canister, but has nowhere to go because there is no evap solenoid to purge the canister.

Check and make sure all of your vacuum hoses are routed correctly. Every SR I've seen has some kind of messed up vacuum hose routing.

If you miraculously have an evap solenoid, make sure everything is hooked up.

If you have no idea what's going on, pull every single hose from the canister and cap off the lines at the TB.

Then take the line that goes from the tank and leave it open facing down to vent. You can follow this line all the way to the firewall and to the fuel tank if you like.

But make sure you leave the 1-way check valve and vent line open to vent the gas tank.

[2-4-0]

Where is this 1 way check valve located?

The gas tank was just out of the car for some work so maybe something happened to it..

[2-4-0]

Disconnected all the vacuum lines that go to the canister and it's still dripping out the bottom?

Anyone got ay ideas on how to fix this?

[g6civcx]

Originally Posted by 2-4-0

Where is this 1 way check valve located?

Between the tank and the charcoal canister. The 1-way valve in the line keeps fluid from traveling up to the canister.

Originally Posted by 2-4-0

Disconnected all the vacuum lines that go to the canister and it's still dripping out the bottom?

Anyone got ay ideas on how to fix this?

I already told you above. Fuel is dripping out of the canister because the vapor doesn't go anywhere. You need the evap solenoid to make the canister release vapor into the engine.

Again, it works like this:

Fuel in the tank evaporates and travels through the vent line through the 1-way check valve and then into the canister for storage.

The evap solenoid operates off of engine vacuum, and at a vacuum threshold, sends a signal to the canister. The canister then sends fuel vapor into the intake for burning.

Since the evap solenoid never gives the purge signal, fuel vapor collect in the canister. Eventually the canister will get full and start dumping fuel. There is a drain line attached to the frame rail.


Here's how you fix it:

Pluck the line that goes from the tank to the canister. Leave this line open to vent.

All other lines going to the canister can be removed. Cap off the port on the TB and any other open vacuum port not being used.

[2-4-0]

The reason I don't wanna do that is that if it does decide to leak agin it'll just be a river of gas flowing out the bottom instead of a steady drip from inside the canister..

It only seems to do it after I fill up.

Is a loud Wooosh sound of air escaping the gas tank normal when you pop the cap off or should i get a new cap that vents better?

[KwKouki]

Originally Posted by g6civcx

Never ever seal off the fuel tank vent line. Pressure buildup = explosion = fire.

you are talking about the hard line coming from the firewall correct? This makes me nervous now.....everyone I talked to told me to cap it off with a nipple. Im not running the can at all.

[g6civcx]

Originally Posted by 2-4-0

The reason I don't wanna do that is that if it does decide to leak agin it'll just be a river of gas flowing out the bottom instead of a steady drip from inside the canister..

Like I said above. First, you need to check your 1 way check valve. You blow air through it. Air should only go one way from the tank to the canister. No air should go the other way.

There should be no fluid in the valve. If there is, something is wrong with your tank or line.

Assuming your check valve work, the canister is supposed to trap vapour. After a while of not having anywhere to go, the vapour will condense and leak out into the frame rail.

Putting the vent line straight into the frame rail won't hurt anything. You're bypassing the canister.

Did you mess up and mix up your fuel lines or something? You could have hooked up the fuel return line to the canister somehow.

Originally Posted by 2-4-0

It only seems to do it after I fill up.

Is a loud Wooosh sound of air escaping the gas tank normal when you pop the cap off or should i get a new cap that vents better?

Yes, it's normal. It would not be normal if there is no pressure.

Originally Posted by KwKouki

you are talking about the hard line coming from the firewall correct? This makes me nervous now.....everyone I talked to told me to cap it off with a nipple. Im not running the can at all.

Yes, I am. You cap the evap vacuum line and the TB line. You must leave the fuel tank vent line on the firewall open or you will have pressure build up in the tank.

Then either it will blow a seal or the tank will explode.

[KwKouki]

Originally Posted by g6civcx

Yes, I am. You cap the evap vacuum line and the TB line. You must leave the fuel tank vent line on the firewall open or you will have pressure build up in the tank.

Then either it will blow a seal or the tank will explode.

hmm.....when I got the car only the hardline was connected, the 2 vacuum lined were cut. There is 2 caps on the TB already so that must be what you are talking about.