When you start the car while the car motor and coolant are cold, is this when it is happening?
If so does it happen again if you cut the car off, then back on after it drops to 750?
If so that would be close to normal, maybe a tad off, but when the car first starts and the motor is cold the fuel system is in open loop, and the car will idle a bit faster till the car warms up and the fuel system enters closed loop.
If this is something that has not always been this way, then as suggested, clean the IAC and put it back in.
2006 Pontiac Grand Prix GT with SC
1996 Buick Park Ave NA