Took it apart one last time. Went over the intake with a fine tooth come, sealed the crap out of everything. New oring on the map sensor, epoxied the suspect nipple 100% shut from inside out, new gaskets again, tested the egr tube and tightened the crap out of it, cleaned the head mating surface again... I mean there is no freaking way this thing can leak now.
Waiting on a new IAC gasket then going to reassemble tomorrow and hook absolutely no vacuum components up. Plug the evap line, brake booster line, pcv, fresh air to the pcv, EVERYTHING! then run the engine, see if its running correct and start attaching vacuum components one at a time and watch what happens.
Speaking of the EGR...its one of the things i just looked closely at for a possible vac leak. Im still baffled how it works, the EGR tube runs from the intake to the block but the valve is at the back of the engine. Can't access it without removing the trans but the port runs through the block on the drivers side. Its fully electronic stepper motor so no vacuum lines to the valve itself but if the tube leaks its a vac leak. Also coolant lines back there that cant be fixed without pulling the trans. It has issues with maintenance but the duratec is a proven amazingly reliable motor. Its in everything, including the new rangers. The 2.3 EcoBoost is just a turbo duratec.
Id take a duratec over any factory ranger engine. Even the 4.0 sohc aint much more power, is heavier, and has more maintenance problems.
Im not talking about @PetroleumJunkie412 building his crazy 2.9, im just talking stock ranger engine options.
Fixed! I think... computers "disired idle RPM" and "actual idle RPM" now match. Unplugging the IAC now causes the RPMs to drop about 150-200 rpms and fuel trims are re-learning. Long term at idle is already down from +15.6 to +9.3 and still adjusting.