I have a 2001 f150 5.4 liter 2 wheel drive super crew that idles rough with surges in the idle. Weird thing is it only does it when it’s 55 degrees or below. So it’s fine now in the heat but winter is coming and the colder it is the worse the idle. Replaced maf sensor.
With the engine idling, take the handle of a screwdriver and rap on the Idle Air Control valve. http://www.rockauto.com/catalog/moreinfo.php?pk=382812&cc=1372452
If the idle speed changes replace the IAC valve.
Tester
Has new valve on it