Hi Jamikest,

Ooops...my bad on the material and location...should have never assumed it's where it is on most other lesser vehicles....My Alfa GTV 625 has it in the same place as the Xfire then...one more reason to like both ;-)

And another small correction to my attempt at deciding whether the popping noise may come from the tank....I meant to have the cap opened immediately after the run cycle and then shutting down the engine.

The reason why I am leaning towards a vacuum issue is due to multiple makes and models where that was the cause of similar problems.

Thanks for keeping things correct Jami