Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Fuel leak help

Guys,

I’ve been trying to locate a fuel leak for a month now with no success. My garage would smell like a gas station overnight. Even when the car sits for a week without starting. I do not smell fuel while driving. Here is what I’ve tried so far:

- added UV dye into my gas tanks, inspected everything like 10 times - there are no visible leaks anywhere
- plugged fuel pump inlet/outlet, pressure tested the tanks through the vent hose: gas tanks hold 10 pounds of pressure for 5+ minutes
- changed fuel injectors
- changed all fuel lines
- changed the vent line
- plugged vents and removed the charcoal canister overnight
- sealed the gas tank cap
- sealed the airfilter
- sealed exhaust outlets

Still smells like a gas station overnight. I am at a loss here, please help!

That’s a toughie. Mind you I had a similar moment but thankfully discovered it was my lawn mower (also kept in the garage) petrol cap that was cracked. I’m not being funny here but given all the checks you have done, I take it that if the car isn’t in the garage then the smell in the garage disappears.

Any other vehicles parked nearby?

My leak turned out to be a fractured weld where the filler tube meets the fuel tank - you had to look very carefully to see where the problem was and I could only smell fuel when I'd brimmed the tank. Some PU sealant around the weld sorted it out.

No other sources of gas in the garage, I would I assume the pressure test would reveal the crack in the filler neck?

What year M3W is your Alex?

Fuel filter can corrode under mounting bracket.
But then i guess you would have fuel spraying out when under pressure so probably not that.

+1 on this, if you haven't already checked the body of the filter you could have a really small pinhole leak under the bracket and the filter will take a while to drop to ambient pressure from running pressure after the pump is shut down. Worth a look and it takes a tiny amount of petrol to stink out a garage.

My leak took a full tank to leak visibly; shop had to use a bit of pressure to find it too. I think with the less fuel, the leaked petrol would evaporate before it became visible.

It was the common cracked forward mount issue and would smell most on the back & bottom of the drivers seat (LHD).

How about a leaking fuel injector?