Realize poster has solved re cleaning IAC. My 2cents on idle.
VCT's are cheap and easy to replace on 1st and 2nd gens. Do replace them on higher mileage units.
First place to go when you have decent miles and idle issues and the dreaded rumble strip or mild misfire/OD shifting issues.... Is coils and plugs. Replace them all as a set, with OEM Motocraft parts (concensus seems to say). It will save you quite the headache. Torque them down good. They sometimes come loose. Yes it's expensive but worth the cash in the long run.
Second place to go (and I don't see many of you looking here) is the cats. The catalytic converters on 5.4 powertrains get destroyed under normal operation, let alone a (commonly) misfiring one. Once I gutted my cats / replaced with new/high flow the difference was phenomenal in terms of just driveability. Power, torque, huge fuel economy difference. It was contributing to the variety of misfire codes along with random coil plug issues. If you have a unit with I'd say 125K+ I'd get new cats. The difference is incredible. And have a look at your old ones. There were little tiny f-kin pinholes left for airflow. The unit could not breathe. Caused all kinds of fkery. Swap or clean your cats. Same time you do your plugs and coils if you want to do justice to your truck.
If you think you have fuel problems... Sending unit on gen2's guaranteed to fail especially in colder climates. Fuel filters get dirty fast as well. Contributes to idle flutter. Also loose manifold could cause the 0174 and others I saw when unit goes out of mix trying to compensate. Clean Mass Airflow Sensor as well, could make a difference.
Don't pop your valve covers to fool with Cam phasers until all the above complete. Chances are you will do an expensive timing and phaser job that may not yet be required. Extremely difficult to diagnose even at dealerships. Best money is coils, plugs, cats. Work up from there. My two cents.
