Check the tube that connects the fuel filler to the fuel tank which starts to split as it ages but isn't immediately obvious. Not sure how old your car is, mine is 2004, but it's a known problem where the tube splits and the first you know about it is the smell of fuel and if you leave it long enough, like I did, the next indication is when you fill up and fuel starts pouring out over the exhaust when you fill up with petrol. It's not noticeable when the tank is half full but fill it up and you get the petrol smell that you describe.
I had this problem in my 2005 roadster and had a row with the Morgan factory about it. The pipe from the filler cap to the tank is made of NBR (nitrile butadine rubber - a fuel resistant rubber) which, however, is inherently very hard and inflexible. It require 10% plasticiser in it to keep it soft. The trouble is that the ethanol now put in many grades petrol leaches out the plasticiser causing the rubber to become brittle and crack. I was genuinely able to crack a walnut with my fuel pipe.
Despite much correspondence the factory denied that this was a 'known problem'.
Yup, Same fault, just occured. It seems to split at the bottom of the hose which means that anything over hald a tank full will result in vapor leaks. The problem is made worse by the fact that for my model, the replacements are on back order at the factory. I was lucky enough to find one in stock at my 'local' Mog shop.
My split hose happen in Italy on a Classic Car Tour (just outside the Ferrari Factory - very embarrassing!) It cost me £220 to have a replacement shipped by DHL (very efficiently I may say). The Morgan factory were obstructively unhelpful.
I found on the interweb a firm than makes silicon seamless fuel & ethanol resistant filler pipes. I gave the details to Morgan but, unsurprisingly, they still fit the rubber ones.
Always handy to carry a reel of self amalgamating tape. Useful for sealing split hoses as a temporary measure. As the name suggests it welds itself together and forms a very water/fuel seal. Not expensive, but so useful.
Neil
Last edited by NeilM; 16/07/1402:21 PM. Reason: Cant spell