engine starts at 1800rpm, once antifreeze temps rise rpm's oscillate 1500/1700

What is your question?

I replaced the IAC because it would stall at idle. When I put back together the engines idles initially at 1800rpm then once atifreeze temp rises rpms oscillate evedry second between 1500 and 1800 rpms constantly. 2002 nissan pathfinder LE 3.5L 4x4

How long has your 2002 Nissan Pathfinder had this problem?

Since changing the Idle air control