ok, 2001 ford expedition 5.4L eddie bauer edition with 94k miles. On first start up after sitting all night, I get a rough idle that last 30 seconds to a minute then runs like new the rest of the day. it does this if the outside temp is 30 degrees on 80 degrees. I have replace fuel filter because it needed it, fixed a small vacuum leak, cleaned throttle body, cleaned maf sensor, check fuel pressure which holds steady at 35-40 psi running and shut off, changed spark plugs do to approaching 100k mile mark, ran 2 cans of high quality fuel injection cleaner through it. no check engine lights..I am out of ideas. Could the IAC sensor cause a very brief rough idle after sitting for long periods then straighten up? That's about the only thing I haven't checked. I also checked the pvc elbow below the IAC sensor. its new and intact. please help. thank in advance