Idle Speed Control (ISC) Round 2

[Lextreme II]

My car idle at 800 rpm but its unstable and sometime stall. I took the ISC out and cleaned. The car idle at 1400 rpm. I wonder why is that. Any suggestion?

 

[Toysrme]

Reset your ECU.
Also, a lot of times when people build new intakes, the IAC/ISC pipe changes diameter, or length substantually.
That can cause idle changes.