petrol blowback when filling up

[Linda]

Could you point me in the right direction, been touring and up until today the filling procedure was ok. I took off the petrol cap today and got covered in petrol as it blew back at me. I filled up and returned home (80 miles) with no problems, but when I returned home I cautiously tried again and again it blew back - I stood back this time! Could you give me some idea if this is a serious problem or what needs attending to. Thanks Linda

[Astromorg]

Too much pressure or vacuum runs the risk of damaging the tank and causing leaks. Not good from any point of view. It's usually caused by a problem with the evaporative emissions control system. This system is simpler in the early models (I think you have a '96) and first points to check are under the bonnet and behind the wheel arch liner of the front left hand wheel.

This diagram shows the system

and its the Evap Valve and the Fuel Tank Pressure Control Valve that need to be checked. That said, an evap valve that's solenoid operated might be expected to generate a warning message/ light and the name of the other valve rather points to it! New ones don't seem to be available, but used ones like this are

https://www.autoreservejaguar.com/xj6-x ... c7714.html

While the pipework to the valve is disconnected, it should be checked by blowing through that it's not blocked.

[Linda]

Thank you for your help. Also you have reminded me to update the car, as, a couple of months ago we bought a 98 model now. Will get this checked asap. Linda