544;

White residue on fuel system components is oxidation of the white metal/light alloy used. It can be easily removed by spraying with carb cleaner and wiping. I'd use this technique to clean residue from fuel bowls, but I'd blast additional carb cleaner and a q-tip or give-away chopstick (from the oriental restaurant of your choice) in there to loosen the particulates which have collected in sumps at the bottom, and follow this by blasting it out with either shop air, or a strong exhale through a piece of fuel line (pinched at the end to increase velocity) repeat until the fuel bowl sumps are nice and clean.

I suggest you open that fuel pump (by unscrewing the glass holding nut at the top), and clean and free it up...chances are good it will come back fine...inspect membrane for cracking...replacement kits are available for this AC pump.

I'd also suggest blowing back toward the tank to possibly send back any contamination which may be in the line.

Finally, I recommend pre and post pump see-through fuel filters...these allow a simple fuel system inspection at a glance.

Cheers