An IAC just bolts on there should be no adjustments needed. A TPS usually needs to be adjusted to a correct voltage usually about .5 volts. Explorers have a PCV hose I think on the rear of the throttle body that can split open and cause part of what you are describing. It has a 90 degree bend in it and if you squeeze the hose while running it may idle up/down. If it's split, pick up a replacement at FORD for a few bucks as it is a molded hose, cutting any other hose to make one will kink and cause it to run just as bad. Hope this may help!
