No starting on its own Possible pump fault?

[andyyy]

Personally I use a air compressor and a rag in the filler cap to pressurise the fuel lines don't go mad tho only needs enough pressure to show a leak don't go putting a few hundred psi or you'll just blow something

Emptying the fuel filter before it refilling means a leak before or at the filter in my experience

I have no idea about the hissing sound your pumps making