i've got a 2003 ford f-150 with a 4.6l 150000 miles. when it is started the rpms are at 2000 for about a min. and a half then it drops to normal when its started cold. when started at opperating temp. the rpms are at 2000 for about 30 to 45 sec then drop to normal. the iac, upper and lower intake gaskets, intake run controler valve, dfbe, low intake and shield, coolant temp. sensor, intake air temp. sensor, egr, egr regulator valve, maf, ecm have all been swaped out no vacuum leaks all line in good condition tps voltage reading of 0.84v l'm at the end of my rope on this and ford has been no help

 

Did u find a solution having the same problem

 

I'm not by any means tech swavy but had this happening to my 01 xlt pulled my air filter put in a k&n reusable air filter noticed some of the hoses attached to the intake were sliding off put them back in place they came loose again so used a couple hose clamps to keep them seated and sealed this rectified that issue hope that helps you out