well maybe you guys can help me . i have 79 blazer with a 5.3 &4l60e and and it had been running great , then last week i put in my nelson tune and now the engine straves for fuel after about 5 min of drive time(at cruises speed) . if i pull over and shut the ign off and crank it back up it'll run fine for anther 5 min maybe an hour . do you think the pump might be a it's limit. i have replaced the filter . thanx ahead of time