AAC valve + Idle problems

[Terminal]

Lately my car has been idling at around 1500rpm sometimes while warm, but then drops back to normal 700rpm. the other day it decided to sit at 2000rpm while cold, then down to 1500rpm. i've noticed a ticking sound in the engine bay which is coming from a solenoid that is located at the front of the inlet side of the engine next to the injector off cylinder 1. when this makes a tick, it will idle up to 1500, then another tick and it goes back down to 700. these ticks are different in sound, so im guessing its the solenoid turning on/off. is this the detonation sensor? what could cause this swtich to go spastic and turn on/off all the time.

Anywho, with the idle at 1500, i cleaned the AFM, no change. i disconnected the AAC valve and adjusted the little screw to set it at 700rpm, then plugged the AAC valve back in and it shot up to 1500rpm. currently i'm driving with the AAC valve disconnected because it runs fine, would this mean my AAC valve is stuffed? is it a bad thing to drive around with the AAC valve disconnected?

Anywho, i've checked the forums for similar circumstances, but it seems im alone with this one. any help appreciated.

[blind_elk]

The "tick" might be the VVT solenoid clicking the valve timing in and out, but don't quote me on that one.

Have you disassembled and cleaned the AAC valve?

Have you checked the "throttle closed" switch in the TPS, although you would normally get a constant high-rev idle if that were causing the problem.

[Terminal]

yeah i pulled the AAC valve off and cleaned it, it didn't change anything. the revs are constantly high, they only drop very rarely, but usually bounce back up once i drive then stop again.

[MegaGTS4]

There is a screw on the side of the ecu that also adjusts the idle aswell as turns on diagnostics, just turn it lightly if you do.

[BenA31]

There is a screw on the side of the ecu that also adjusts the idle aswell as turns on diagnostics, just turn it lightly if you do.

does that control the idle speed or the idle mixtures? cos i haven't heard of that before.

[Terminal]

the screw only adjusts if you have the AAC diconnected while doing it. if it's connected, the ecu compensates and there isn't a change. when i initially disconnected the AAC it almost stalled, so i had to turn it up to 700rpm to get it to run smoothly