Car overheating while engine is off

[fixkick]

if cold start goes, 1800 rpm and you see DP retracs with eye balls, in say 15seconds and last  RPM is  at 750 ,then that IAC is 100% dead.

correct would be 1800 for 15sec then 1200 (about) then after water hit 150f , 750 to 850 RPM regulated ISC.
note the 3 phases there. not 2.
the 2 high numbers are based on water temps at first cold start
when engine hot there are 2 RPM.
ISC is off line hot.
say 1200 then 750  hot. 2 steps phases.
we get used to this fast once the cars engine runs right, all do that every TBI made.