How do you keep your truck runnig when it gets 80 plus degrees on 2008 Chevrolet Silverado 2500 HD

pulling 14' enclosed trailer 3500lbs total wt. bucking wind 1/4 tank of fuel ding ding reduced engine power comes on drops to 35 mph tells me to change fuel filter [not the problem] sometimes if you pump up the primer on top of filter it will take off again i think the code is fuel rail pressure it only does this when it gets hot out no one seems to know the problem if i stop and fill tank that helps check engine stays on for a while and then goes off and if the weather cools off no problems this is driving me nuts truck has 167000 miles on it this is costing a fortune in filters also when it gets 10 degrees or lower it does the same thing