Hi everyone

I have a 2001 Nissan Sunny that is idling high at around 1700rpm even when hot. It will also rev between 1200rpm and 1700rpm on its own some times. I borrowed a scanner and found the mass air flow sensor voltage wouldn't change from 1.8v from 1700rpm to around 3000rpm. I then replaced the sensor and it is still idling high. I have sprayed brake cleaner around as much of the intake system as i can and it doesn't affect it, also when i took the brake booster hose off it would almost stall but if i covered the fitting partially it would idle down. This seems strange that adding more air would make it idle lower when vacuum leaks should make it idle higher. I have also unplugged the idle air control valve and started it again and it idles higher to around 2500rpm and when plugged back in a started again it goes back to 1700rpm. Could this valve be sticking not letting it idle? The engine also seems to warm up quickly but i guess that is from the higher idle. If it helps the engine is a QG15DE which i have had a hard time finding manuals for. Also there is no check engine light on.

Anyway if anyone has some ideas that would be greatly appreciated.
Cheers