FYI-

The transfer or siphon pump will show a speciifc failure mode: you will 'run out of gas' with apprx 1/4 to 1/2 a tank of gas showing. The car will run fine until the fuel level drops low enough that the fuel level doesnt naturally spill over the 'hump'. The one 'side' of the tank drops belw the saddle and the side with the main pump will run dry. in earlier cars you could display the fuel levels in L, R and combined. Just looking at these will tell you when the siphon pump dies or is dying.