Unstable at idle speed

Vladimir.
First, Your idle speed is too fast at 1000-1100.
Disconnect iacv. Adjust idle to 850.
Reconnect iacv
Check idle again.

I have sent an e-mail to someone who deals with the ECUs etc. If and when I get a reply I will let you know.

When the engine warms to operating temperature idle is fine 850-870 RPM. If you do not touch anything and not pressing the accelerator is idle with no variation. But when I press the gas pedal RPM jumps to around 1000 -1100 RPM with variations of about 100-150RPM. Then after a few minutes to stabilize the speed at approximately 870 RPM and the tachometer needle does not vary. Also for example, when I change the speed from the second to third at 2000 RPM, after pressed the clutch down the revs raise at 2200 RPM.

CJJ, thanks.

"MYSTERY - ROVER IDLE PROBLEM" - Reset the ECU
Disconnect the battery and put the live lead to the earth that will discharge the system leave it like that for an hour then re-connect the battery and then start the car as soon as it start push down on the throttle and hold it at 2000 rpm for 3 mins then release. See how you get on with that let me know as doing that will re-set the ecu and holding the RPM will help it learn its parameters again.
:yesnod:
It was not the desired result.

But after 150 miles flown, learn its parameters again and "MYSTERY - ROVER IDLE PROBLEM" is resolved in my case.
Tachometer needle is stable at idle and respond "sharply" as a sword.
Reached the desired result.
My happiness has no end.
:woohoo:
Thanks to all.
:broon:

That's great news! :yesnod:

Here's the video. :yesnod:
Before (dark)

:rant: :bang:
After (daylight)

:lol: :broon: