Engine Performance problem
1998 Subaru Outback All Wheel Drive Manual 138000 miles

1 year ago almost to the day, I put a new fuel pump in my Subaru...And it's been great until the last 2 Sundays. I live in the mtns. and the weather has gotten cooler. Last Sunday night I filled up my car, 2 hours later started a cold car and drove about 45 minutes when it started getting slower and slower , sputtering and cut off. Then sputtered and ran roughly when I tried to start it,and after taking the cover off the fuel pump, heard it running and went and started the car...drove 2 more hours straight - no problems. And no more problems all week long. (work in a warmer climate at a lower elevation)....Then a week later, Sunday night again, filled up the car during the day, left for out of state job 3 hours later (night and colder) drove 45 minutes and did the same thing. When I when in the back to listen to the fuel pump....the fuel pump started working I heard some gurgling from the fuel pump and then it started. No more problems, drove 2 hours perfectly. Running perfectly. What's up? Do I need another New fuel pump?