Tim, every time I change a fuel pump, I cover the moving parts with lots of STP mixed with motor oil. I don't want it like honey, but the oil needs to 'hang-on' until engine oil washes it away.
Some parts get minimal oil from a 'slinger' or just from oil vapors. Timing chains (and gears) are notorious for being oil-starved. That's why they stretch so soon. If the timing chain doesn't get much oil, you can imagine the fuel pump eccentric doesn't either. But, these components tend to last a very long time, so it's hard to argue with success; they must get enough lubrication from somewhere.