Evaporating fuel mystery

[FERGTS246]

Hi, having been suspicious of my fuel evaporating I now have concrete proof. I put my Flaminia in my garage about 5 weeks ago with no less than 20 litres in it.
I took it for a 15 mile spin yesterday and I ran out of gas.
Are there any known causes for this or potential weak spots in the fuel system when it could evaporate from?
I haven't seen or smelt any evidence of a fuel leak anywhere.
Would blocking the fuel tank breather pipe in the rear wheel arch, when its parked up for a while, make any difference?
At over £1.60 a litre for 97 octane, its getting a bit expensive!
Thanks in advance.
Chris

[peteracs]

Hi Chris

If you garage the car and you have not smelt any strong petrol fumes, then I wonder if the petrol is being lost whilst you run the car, ie between the fuel pump and the car whilst driving?

I would check for cracked/degraded rubber fuel lines if they have not been replaced with ethanol resistant types in recent times.

Peter

[Mikenoangelo]

If a fuel pipe leak is the answer you might be able to locate it by letting the engine tick  over to get a  bit of pressure as you inspect the pipe and watch for drips.
I' d be surprised if evaporation would cause such a huge loss.

Mike Clark

[FERGTS246]

Hi, Thanks for that, much appreciated.
Chris