Had a fuel smell for years on my m3, changed everything except what was causing the smell. Then one day on start up it spewed petrol all over the engine. Injector "o" rings. May not be your problem but worth thinking about.
Talking of fuel... I happened to be reading the owners manual the other day and noticed that the 4.4 is supposed to be run on 98 octane. The last three or four fill ups have been with 98 and I now get a better average mpg. Up from 18.6 to 20 ish. How about that..