Fuel Tank Pressurisation

[astonman]

Hi everyone,
I've got a T350 which has suffered from fuel Tank Pressurisation since it was new.The recent hot weather has just made it much worse.
Checking through the breather system,the carbon canister is upside down,does this matter?
Cheers.
Simon.

[Oneball]

Not sure if it matters but wouldn’t have thought it’d help.

If it’s upside down maybe the pipes are on back to front too??

[Steve_D]

Remove the pipe (tank forward) at the carbon canister. Remove the filler cap. See if you can both suck and blow down the pipe.
If not then you have a blockage. I suspect the pipe is trapped below the tank but it may be anywhere along the chassis. Perhaps cutting the pipe as far back as possible and again performing a 'blow test'.

Steve

[astonman]

Thanks Steve,I'm having difficulty identifying the breather tube from the tank.
I've found a pipe that comes out of the front near side rear wheel arch and then connects to the canister just behind it.
Does the breather go to the roll over valve ( hidden adjacent to the seat belt mechanism I believe?) from the tank and then to the canister?
Thanks.
Simon.

[Steve_D]

The route will be:-
Tank, probably up in a loop as high as the bodywork will allow, down into the rollover valve, out to the canister.

I'm not familiar with the 350 layout but find it surprising if the canister is at the back of the car as it requires a vacuum connection to the canister and vacuum hose is more expensive than fuel hose. Are you sure you are not confusing canister for fuel filter.

Steve

[astonman]

Hi Steve,
The carbon canister on the T350 and Sagaris are definitely mounted in the front of the NS rear wheel arch.
Cheers
Simon.

[astonman]

Well, I've found the Rollover valve,which TVR had set at about 20 degrees from the vertical!
Drilled out the fixing rivets,,,,broken the plastic valve ! And now will get a new one,which I will position at the vertical not 20 degrees off!
The existing pipe work shows no blockage,although the Rollover cable has a distinct flow reduction for tank pressure

[konrad.holl]

astonman said:

Well, I've found the Rollover valve,which TVR had set at about 20 degrees from the vertical!
Drilled out the fixing rivets,,,,broken the plastic valve ! And now will get a new one,which I will position at the vertical not 20 degrees off!
The existing pipe work shows no blockage,although the Rollover cable has a distinct flow reduction for tank pressure

So, where did you find the valve? I was told it was in the B pillar, just behind the passenger door - never bothered to check, although my T350 is suffering from the same problem.

[astonman]

Hi Konrad,yes it's in the B pillar,it's a bit awkward to get at.
I think I may have improved my venting,but it will take a run out on a warm day to prove it.things are a lot cooler here now!

[astonman]

I was able to suck and blow into tank and venting to carbon canister,all worked, although a bit restrictive to flow,hope re mounting the valve nearer to the vertical will improve things.
At least I didn't have to take the tank out to check for a blocked vent pipe.

[konrad.holl]

astonman said:

I was able to suck and blow into tank and venting to carbon canister,all worked, although a bit restrictive to flow,hope re mounting the valve nearer to the vertical will improve things.
At least I didn't have to take the tank out to check for a blocked vent pipe.

Cheers for that! Will put it on my list for winter...