Fuel Leak / Charcoal Canister (1 Viewer)

[Von Hayek]

I have a friend with a '95 80 I was hoping to get some help with. The fuel filler neck had just just been replaced after running for a very long time with holes in it. Here is the description of the problem:

"We got fuel in it, ran it for a bit and then sitting overnight we have fuel dripping out the vent line from the charcoal canister dripping down the frame rail (charcoal canister has fuel in it), we came in to fuel puddled on the floor. This is a new one for us so I thought I’d check and see if this is something you’ve seen happen before. Our best guess is the system is over pressurizing now that the tank and filler neck don’t have leaks but not sure why… when you open the gas cap you can hear pressure escape."

 

[jonheld]

Replace the charcoal canister.

 

[Road Apple]

Here’s some notes and links to replace the canister. Avoid topping off the tank helps. Ethanol free fuel helps in high temperatures and altitude.



“One thing that had me stuck for a few minutes that did not seem to get addressed in this thread is that the bottom part of the bracket that holds the container makes contact with a section of the wire loom once a larger canister is installed.

I found a video that shows this easy trick (flipping the bracket 180 degrees) to avoid making contact with the wire loom, in case someone else runs into this issue:

Charcoal Canister - Great Option! - https://forum.ih8mud.com/threads/charcoal-canister-great-option.412261/page-33

I would toss the "splash cap" and run fuel hose to the oem air inlet tube (takes air from the frame rail). with how extreme the back flow can get in the 80, dumping raw fuel into a hot engine bay makes me feel uncomfortable.

I was forced into replacing the charcoal canister in my LX450 with the AC-Delco 215-153. I have been getting fuel tank pressure for a while now, and the OEM canister failed the tests in the FSM.

As others have said, it is a slightly larger diameter so a pair of 1/4-20x2.5" bolts w/hardware were a good fit. Again, as said the lower bracket has to be flipped and a length of 10mm tubing should be added from the canister's vent port to the OEM vent. Not the neatest routing, as it needs to cross the other 2 ports on top.”

In hindsight I should have removed the EFI fuse for a while and allow the ECU to relearn. My idle once at normal operating temp was somewhat unstable and around 1100 which has never been the case. After my first drive, it came back down to a steady 650 where it always should be.

 

[Von Hayek]

Here’s some notes and links to replace the canister. Avoid topping off the tank helps. Ethanol free fuel helps in high temperatures and altitude.



“One thing that had me stuck for a few minutes that did not seem to get addressed in this thread is that the bottom part of the bracket that holds the container makes contact with a section of the wire loom once a larger canister is installed.

I found a video that shows this easy trick (flipping the bracket 180 degrees) to avoid making contact with the wire loom, in case someone else runs into this issue:

Charcoal Canister - Great Option! - https://forum.ih8mud.com/threads/charcoal-canister-great-option.412261/page-33

I would toss the "splash cap" and run fuel hose to the oem air inlet tube (takes air from the frame rail). with how extreme the back flow can get in the 80, dumping raw fuel into a hot engine bay makes me feel uncomfortable.

I was forced into replacing the charcoal canister in my LX450 with the AC-Delco 215-153. I have been getting fuel tank pressure for a while now, and the OEM canister failed the tests in the FSM.

As others have said, it is a slightly larger diameter so a pair of 1/4-20x2.5" bolts w/hardware were a good fit. Again, as said the lower bracket has to be flipped and a length of 10mm tubing should be added from the canister's vent port to the OEM vent. Not the neatest routing, as it needs to cross the other 2 ports on top.”

In hindsight I should have removed the EFI fuse for a while and allow the ECU to relearn. My idle once at normal operating temp was somewhat unstable and around 1100 which has never been the case. After my first drive, it came back down to a steady 650 where it always should be.

This is excellent. Thank you.

 

[LandLocked93]

There is a possibility of renewing the factory canister but it really depends how badly the check valves are stuck/corroded.

I used a few drops of Oil Eater down the ports to soak the check valves/balls. Then used q-tips to reach into the ports and clean out as much as I could.
Then re-ran the FSM eval process - first with air, then just let OE flow through from top to bottom.
Repeated several times until the eval process passed.
Also replaced the gas cap for the heck of it.
A thing about Oil Eater is that it evaporates, so it's useful in this case leaving no residual in the canister. (it's also biodegradable fwiw) I use it alot for cleaning/degreasing chores actually, especially undercarriage soak before pressure washing.

Anyhoo, this was 4 years ago or so and haven't had an issue since. No tank pressure (tho if you read the gas cap it states that there will/should be a little at times), no fuel smell at any time or at any elevation, and no further 'boiling in tank' issue which was the catalyst for my trying this to begin with.

 

[Von Hayek]

More information:

"We tried the new canister, and new vacuum control valve, Weirdly enough we are getting fuel dumping out of the tank through the vent tube even when the canister and vacuum are disconnected. Really makes no sense."

 

[Von Hayek]

I thought I would follow this up with the solution that was found:

"It was a multi-part problem. There’s a vent in the tank that was stuck, not allowing built up pressure to escape. The other problem was the vacuum control valves for the evap and idle were both malfunctioning and producing too much vacuum."