As for fuel pump, you wouldn't know when it kaput. The thing that kaput is the float. Mine have the exact same problem, suddenly it detect no fuel, suddenly all come back. Suka² it goes half a tank then restore. I'm just bearing with it, as long my trip meter reaches 400km, I'll go fuel up full tank. Until 1 day I switch key to ON but no more sound from fuel pump, then I know it's time to change. My next fuel pump probably going to be GaGa also I have not measure, but most probably will detach the fuel pump, blast it with diesel first(prevent catch on fire) then bring the whole damn thing to sparepart shop ask the fella bring out a GaGa fuel pump and compare I wouldn't even wanna tell the sparepart fella whether ayam using it on what car.

Anyway, recently the symptoms seems reduced or close to none. I think cleaning up the tank does help Ran a bottle of this, split 3 full tank of petrol to finish it. I think after that no longer see the fuel indicator sudden drop liao Shall see