So I have high idle for my 96' 240, and I had it since I got the car which was a while ago. The last owner did a motor swap from a '97 KA auto.
So the thing is that the idle is constant and not hesitating but it it kind of high at around 1400 RPM sometimes. When I start my car in the morning the idle raises to 1500-1600 RPM then drop after a while of idling. At cold weather it drops to about 1000 RPM but on a hot day, especially when I turn my A/C on it is about 1600 RPM!!!!!
I checked many things, I know that it might be caused by the AUTO ECU but it is a manual ECU just like it should be. I checked that it might be the MAF because the prev. owner put a POS oil type air filter that ruins Mass Air Flow sensors, I unplugged it but nothing changed so it's not the prob. I did the same thing with the throttle position sensor (TPS). I recently cleaned my IACV inside out but it's the same shit.
I did a check engine light scan because it was on but it only showed problems of Speed sensor, and EVAP.