Hi all I have a 1997 XJ6. I have noticed lately that every time I take the fuel cap off there is a big release of air that comes out of the fuel tank. Tonight I took the car to the petrol garage after it had been sat for a week and when I undone the fuel cap it shoot up about 6 inch’s and almost took my eye out. Does anyone know what would be causing this ?
cheers all

 

Rochester valve failure likely. Either that, or there is a blockage in your fuel tank vent line.

With pressures like what you're talking about, you will want to resolve this before you spring a leak in your fuel tank.

 

that for the reply mate. I will and google what this valve is now

 

There are 2 versions of the EVAP system on the X300 , one with and one without Rochestor valve

Some have plumbed in the valve backwards

There should be a simple blow in tubes test , but probably easier to just replace with fresh part

There is a Delco ( GM ) equivalent # 214552 or 214 - 552






The difference is if you peek under the car without jacking you will have one rectangler box vapor canister on the left just fwd of the rear tire

The other is if you have 2 , one on ech side of the car

See page 60

jagrepair.com/images/Training Guides/801S - 2000.pdf

The second version is electrical that you can check at the ECU connectors

Black 24 and 31 , should not be open or infinite resistance

This electrical valve version may have to do with California emissions or US market as a whole as it's installment is mixed around on production , threw me for a loop and gave me a spot of stumble under my bonnet

 

I would just remove it entirely and pipe it straight to the charcoal canister.

I don’t believe the AC Delco part works as well as the original.

Apparently the original can be popped opened and cleaned, supposedly will work like new then?

 

Thanks for the replies everyone l. I will get under the car tonight and have a look. Could this also be linked to why I can only fill the fuel tank to 3/4 from empty? I can fill the tank to 100% full but only if I start with 1/2 a tank if more

 

I have the 3.2 xj6 not the 4.0. Will may car still have all the parts in the same location?

 

On my UK car I think this is the location of the valve.

 

that’s for that mate 👍🏻

 

When I had my 91 XJ-S that fuel tank pressure drove me nuts. Long story short, get second gas cap & drill a 1/16" hole. Never had a woosh after. I know some will say that's a "no no" but so are "95 mph Italian tune ups" etc