I have a 98 f150 with the 4.6 4x4. When it's really cold outside the truck will not start and rev up to about 1500 rpms like it should normally. It will only idle at about 700 for a few minutes and then slowly creeps up to almost 1000. It's like there's a load on the engine not allowing it to run properly. When I start driving there's a slight whining/squealing as well. I feel like something is seized up or not turning freely such as a pulley. Would the ac pulley cause this?