There was no whiff of petrol with my Volvo.
The hoses had become cracked and porous, allowing air to be drawn through the rubber, but didn't allow petrol to escape.
It really does sounds as though you have an air/fuel problem somewhere.
If you can send a personal message to portland_bill and rallycing, they may shine some light on the problem. They both have a lot of knowledge and experience.
Ah .. just seen your post saying you'd cured it? Wasn't the fuel pressure regulator, was it..?