I have a 2005 GMC Duramax with about 50,000 miles. I am towing a 10,000 pound pull type travel trailer and in the past 24 hours have noticed starting taking longer than usual. It seems to have lost some power. The truck has an Edge chip installed. The temperature is 5 to 8 degrees hotter than it has been. I had the fuel filters changed at a a Chevrolet dealer. The problem is no better. I noticed a drip from the bottom of the fuel filter and think I have it stopped. I am not sure the problem is solved. It is taking longer to start each time. Any suggestions?