A CP3 upgrade is the way to go for sure, it is more reliable and efficient, but I would recommend if you can't get it changed to replace filter, and add some diesel fuel lubricants like powerservice to the fuel just to give yourself a little extra security. It really is almost impossible to tell when they will go out, it could make the trip, or fail at some random time during.
If you pull the metering valve and there is nothing there it still could on the way out, you can also carefully clean around the pump and pull it to check the roller and cam lobes to see if that is showing signs of wear. Wish I could tell you more, but this is one of those things that you just don't know how long it will go before it goes out. Mine lasted 206,000 miles.