If it's the original pump you might want to replace it just on the basis of this indication that it's going south. At 180K you're about due; they don't last forever. A fuel pump is not that difficult to do yourself (even in your garage on jack stands), and it's not too expensive. If you get stranded because your pump failed it could cost you a lot more than you'll save by trying to squeeze a few thousand more miles out of your old pump. And while you're at it, definitely change the fuel filter.