dth0ng69

Okay I have a d16y7 all stock except I took out the air intake duct, and resonator.
When I first bought the car the idle was pretty low around 300rpm and the car was vibrating a bit. I did a tune-up (Dizzy cap, rotor, spark plugs, and wires, and air filter) and changed the pcv valve. It still didn't really help the low idle.

So I adjusted the Idle set screw behind the throttle body, and that actually helped the shaking and vibration during the idle. I adjusted to what I wanted the idle to be at 650rpm.

I noticed that in the morning when I turn on the car after the is warmed up, my idle didn't stay where I set it at, it was idling around 400-500.
later on in the day when I drive the car I notice that it idles normally like where I want it.

When I turn on my lights during night I notice that it idles pretty high like around 900-950rpm
and just tonight when I got home, I let my car idle when I got to my drive way and turned off the lights for a few minutes it still idled around 800-900rpm

I'm pretty stuck.. Is my IAC messed up? the idle is pretty constant and doesn't move around but it idles pretty random. I never changed the fuel filter, but I doubt that could be the cause of this.... any help/feedback suggestions would be great
thanks for reading.