Idle unstable in past few days

[baksa]

This is something that doesn't happen always, but suprised me few times in past 7-10 days.
My car was idling unstable since when I bought it a year ago. By unstable I mean that it was idling about 600 rpm and 20-30 rpm up or down.
Last few days it started to worry me.
Sometimes when I'm stending on traffic light, or when I release gas pedal, my revs drop down nearly to zero, causing engine to nearly stop, but it emerges from zero and comes back to 600, but when I stop,the car revs itself to 1500-1600 rpm, and then comes back to 600.
Seems very strange when car revs by itself, and it scares me sometimes.
Anybody experienced something like this and what is the problem, I'd like to solve it soon as possible.

[Rustam]

This is something that doesn't happen always, but suprised me few times in past 7-10 days.
My car was idling unstable since when I bought it a year ago. By unstable I mean that it was idling about 600 rpm and 20-30 rpm up or down.
Last few days it started to worry me.
Sometimes when I'm stending on traffic light, or when I release gas pedal, my revs drop down nearly to zero, causing engine to nearly stop, but it emerges from zero and comes back to 600, but when I stop,the car revs itself to 1500-1600 rpm, and then comes back to 600.
Seems very strange when car revs by itself, and it scares me sometimes.
Anybody experienced something like this and what is the problem, I'd like to solve it soon as possible.

I doubt that this is the problem but I am determined to wear my keyboard out telling people about evaporative purge valve - affects idle performance. Search for these words, I recently posted a message.

[BillionPa]

auto trans i assume?

[Rustam]

auto trans i assume?

Why?

[Rob]

Could it not be the ICV?

[joshua43214]

Start with cleaning the IVC and the throttle plates, this is a common cause of erratic idle. Its a good idea to elimate the IVC as a cause before you dig any deeper.

You can try standning over the engine as it is idling and when the idle dips, tap on the ICV and see if the idle flattens out. Sometime the valve just gets sticky and will need to be replaced.