Yes, thats normal. Its more than likely because the EBPV is closed, and the truck is COLD, and not isnt causing a good combustion in the chamber.Im a new 7.3L owner and have been letting my truck start and idle for about 5min before driving with this 20degree weather here in michigan. I did notice yesterday that the truck for the first 2 miles or so was very slow to accelerate no matter where the pedal was at. I was just trying to get up to 55mph not putting the pedal to the floor. Is that normal in the cold??
Try to let the truck warm up for 10-15 minutes when its cold out. 5 minutes wont do much at all.