Fuel tank breather

[Tom D]

The photos below show what appears to be yet another modification made by my +2's previous owner. I assume it is meant to be an improvement to the factory fuel tank vent tube arrangement. I haven't driven the car enough yet to determine the effectiveness of this arrangement, and I don't even see how this apparently closed system offers any breathing at all.

Thoughts???

[mbell]

Looks like the evap setup for late federal +2. Not sure if it's been adjusted or standard thou.

[Tom D]

As I inspected things further, it turns out my tank vents to the filler neck (photo below). Is that a later +2 development or could it mean I have a Spyder fuel tank? I've read in the archives about problems getting that system to vent properly while avoiding gas spilling on RH turns, but I'm not sure I saw any consensus about how to solve the problem.

Also, if the system in the previous photos is just for evap, would it be a mistake to simply remove/blank it off? I suppose I would notice more fumes inside the car. Presumably the long cylinder behind the tank is charcoal type canister? Whatever it is, it's very obtrusive and presents a challenge when retrimmng the boot interior.

[mbell]

It's federal setup see:

http://rdent.com/manuals/plus2/fuel_system/la.htm

Added to late US spec cars to meet US standards, not allowing venting too air.

[Tom D]

Thanks, I should have checked the parts manual. So the cylindrical tank is actually a catch tank. That explains why its pipes lead nowhere, as the PO already removed the charcoal canister it would normally feed to.

With no canister, the system must currently be venting through the filler cap. I may need to drive the car a bit and see if there is in fact a leakage problem on RH turns, in which case I suppose I'll need to replace the missing charcoal canister. Unless anyone has any other ideas....

[Tom D]

Just to wrap this up...

I ended up removing the old evap catch tank since there is no longer any carbon canister for it to feed into anyway (thus adding some nice lightness). I then ran a very small fuel hose (3/16" ID) from the evap pipe on top of the tank down through a hole in the boot floor, per forum archives (this should provide plenty of air while driving, while the large vent to the filler neck should provide an air escape while filling the tank). I still need to verify my filler cap is leakproof, as it no longer needs to provide any vent function.