However, it should be noted that most often this malfunction is caused by a failure of the throttle position sensor installed in the throttle assembly cover..
… contamination of the throttle valve itself or the suction of foreign air through loose hose connections attached to the intake pipe. If cleaning the throttle valve or tightening the hose clamps does not restore idle speed, contact specialists to replace the throttle cover or replace the throttle assembly as a whole (see "Removing and installing the throttle assembly").
In addition, it should be taken into account that the "floating" of the crankshaft speed at idle of an engine equipped with a variable valve timing system, and the stopping of such an engine when neutral gear is engaged and the accelerator pedal is released, can be caused by a malfunction of the electromagnetic valves or the engine control unit.