Yes to the above
Just to add 1992 4.0l manual trans will idle at 625, automatic at 750, that's warm engine idle, in gear automatic should go up to 800 approx., these are "target idles" in the computers memory.
Cold engine idles as high as 1,400, this is based on outside temp, which is engine temp on cold start, it should drop to about 1,100rpms in under 1 minute, then warm engine idle after 5 to 8 minutes.
If you unplug the IAC valve on a warmed up engine then idle should drop down to 500 or engine should stall, either is good it means no vacuum leaks.
If idle stays higher than 700 then there is a vacuum leak, or as enjr44 said someone has messed with throttle position sensor(TPS) adjustment, looks like idle screw........it ain't
An IAC Valve wouldn't be much good if engine could idle higher than target idle when IAC is fully closed, not much point in even having it lol.
So throttle plate fully closed and IAC valve fully closed should have warm engine idle of about 500, lower than manual trans target warm engine idle, this allows IAC valve to set 625rpm idle even with small vacuum leaks that occur over time as engine gets older and hoses get small cracks, these don't effect operation until they get bigger.
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