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2007 Forester 2.5x 5 speed manual
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13 Posts
Discussion Starter #1 (Edited)
Hello all, this is bit of a long one. Hopefully, this can be of some help to others if I figure this one out.

Ive been the proud (frustrated?) owner of a Red 07 Forry for the past two years or so now. I've been having issues with the fuel system since the early days, whether this be a CEL caused by a small leak (solved, thank you to all who posted on these forums!) or the tank not venting properly and building pressure while driving (also solved, also thanks!). However now I've got another problem with this evap/fuel system... Gas tank cannot fill. No CEL's.

In effort to solve this issue, I have now removed the gas tank and set up the fuel system on the bench (tank, canister, the whole works) so I can better troubleshoot each component.

Currently, when I apply pressure through the filler neck the tank just builds pressure - it cannot vent through the FTVV, this valve seems to operate in reverse of what one would expect. That is it allows air into the tank, not out of the tank. It can only vent through the filler neck itself. I've replaced the shut-off valve, PCSV valve, canister, and Fuel tank vent valve (FTVV), so I'd like to think they are working properly, but this seems unlikely given my situation. So, does anybody know what the proper flows of gasses through this system should be? A diagram would be awesome.

Also, glad to return the favor if you have the same/similar problem. This forum is an incredible resource for fixing these cars.
 

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1999 S/Turbo SF5 Auto
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93 Posts
I have a 1999 model, so things may be different, but here may have some similar things too....

When you say you can't fill the tank, what happens when you try? My model just allows air out the filler neck as the fuel goes in.... so does yours have some kind of seal round the delivery nozzle to prevent this?

On mine, the cap will only allow air into the tank when the pressure inside the tank drops e.g. as the fuel cools down at night. Any pressure built up in the tank by evaporation will be piped to the canister and then burnt in the engine when you are driving along. I have diagrams if that will help (just need to fix up my scanner!)

Paul
 

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2007 Forester 2.5x 5 speed manual
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13 Posts
Discussion Starter #3
RESOLVED!! I ended up replacing ALL fuel/gas/evap lines with replacements. This includes the metal lines, which were completely full of rust/water/debris. I guess the previous owner had some fun in deep water...

Paul, There is no seal where the filer nozzle goes in. Thanks though!
 

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1999 S/Turbo SF5 Auto
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93 Posts
RESOLVED!!

Paul, There is no seal where the filer nozzle goes in. Thanks though!
Very glad you've resolved this :) Just still mystified how the blocked evap lines would stop the tank being filled?
 

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2007 Forester 2.5x 5 speed manual
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13 Posts
Discussion Starter #6
I'm unsure. My best guess is that the hose connecting the vent at the top of the filler neck to the FTVV must remain unobstructed in order for the FTVV to operate properly when fueling.
 
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