VW Golf TDI fuel leak

[Tom678]

I recently bought a 2001 VW Golf TDI. I have noticed that when I park it on a steep incline that I smell fuel when the engine is off. My driveway is steep and I usually park it facing downhill. I have sometimes noticed a small fuel stain on the ground under the engine when I park it this way. When I feel under the fuel injector pump my hand will come away wet. I have taken the car to two different mechanics who spent a total of 4 days trying to replicate this condition to no avail. For now I don’t park on steep inclines and have mounted a fire extinguisher on the drivers side. Any ideas as to the cause and fix would be appreciated. Thanks, Tom C