Mercedes Benz repair: ques on a160 petrol smells coming from vents, class mercedes, air vents

Question
1999, A class mercedes, 38,000 miles, vehicle is in uk, london....we bought it and in test drive there was no petrol smell what so ever, after driving around for while we began to smell some strong smells coming from the air vents (petrol), had it checked out but at that time there was no smell, its on and off but definately from air vents any ideas plz would be great help

Answer
Answer:
This should be a very small weeping fuel leak.

You need the engine compartment clean, before attempting to find the location of this leak.

All fuel O rings, lines, seals, and unions are suspect at this moment.

A torch (flash light)and mechanics telescoping mirror will be needed.
http://imageserver.isnweb.com/KDT2109.jpg
http://www.tomgpalmer.com/images/FLASH%20LIGHT.jpg


Begin at the fuel injectors and search in twenty five millimeter sections, (mark where you have been with a Crayon).
Do not surrender until reaching your fuel tank.