I'm a little confused about this part and what it does. I read about them going out all the time, and how much they cost to replace. Is it electric or mechanical? Are there any alternatives/ upgrades?

 

The VP44 is the Injector Pump, found under your APPS. It pumps your fuel at a very high PSI into the injectors. They usually fail to do your Lift Pump failing, or the electrical on them burns up They are run by a timing gear in the front of your engine, with the electronics coming from the APPS.

 

A new one usually goes for about 1100-1200USD. And can be installed by most people that have a decent set of tools. Theres not really an upgrade to them. However there are a few HRVP44 (Hot Rod) that adds from 50-80HP to your truck.

Out best bet it to keep good fuel pressure to the VP and keep it lubed, and see what happens...