Zip's Nuka Fix

 refers to an unmarked and repeatable quest in Fallout 3.

Zip in Little Lamplight trades various items for Nuka-Cola to satisfy his Nuka-Cola habit.

Note
If Zip gives you a 10mm bullet, he calls them "lucky," but there is nothing special about it. He does not accept Ice Cold Nuka-Cola or Nuka-Cola Quantum.

The Lone Wanderer says he will give an "ice cold bottle" of Nuka-Cola in the dialogue tree, but a regular Nuka is taken from inventory and is required for the quest.

Bug
It is possible that sometimes he does not want Nuka-Cola from you and instead says something bad or good about you regarding to your karma. Try talking to him a few more times and he will eventually say something about Nuka-Cola, then you can activate this quest by speaking to him about it. This may not be a bug, seems like a random speech event too.

Reward
One of the following (not a complete list!):
 * 1 10mm bullet
 * 24 5.56 mm bullets
 * 1 Crunchy Mutfruit
 * Mentats
 * 20 Microfusion Cells
 * 1 Stimpak