When you switch off your car, and the fuel pressure drops to Zero,

How much gas leaked back one way or another.

1. a tablespoon
2. 1/4 cup
3. 1/2 cup

I dont think it would take much, any Idea ?

 

Seeing as how it's going from ~35psi to 0psi... it would probably be 1/4 to 1/2 cup.

 

I knew it would not be much, liquid is easy to pressurize. Think I will actually crack open a connection, and hold a measuring cup under and catch the gas, and see, bet its about a quarter cup. I have to re-position my fuel pressure gauge anyway so that would be a good time, tho under pressure could be a mess. Maybe install a tiny brass valve, then drain, see what it is, and remove the valve.
Hope you have alot of nice driving roads in Utah, never been there.