Just to be sure
was this a new IAC or was it used? (adjusting used IAC can damage it)
Can you be sure adjustment you made was within these specs
The IAC valve may be damaged if installed with the cone (pintle) extended more than 28 mm (1-1/8 in). Measure the distance that the valve is extended before installing a new valve. The distance from the idle air control valve motor housing to the end of the idle air control valve pintle should be less than 28 mm (1-1/8 in). Manually compress the pintle until the extension is less than 28 mm (1-1/8 in).
Red 1996 SE Parked so sad
White 2001 Montanna EXT
Grey 2001 Nissan Sentra OUCH! cheap car for now