Originally Posted by phunk

the gas tank is divided into 2 halves, bridged only at the top. once fuel goes to the driver side, the only way to get it back to the passenger side is to either slosh it back with a hard left turn, or wait for the fuel pump module's secondary function of in-tank transfer to slowly pull it back. however, if fuel pressure drops, the module cannot transfer it back because the siphon is powered by fuel pressure.