VW Bora Automatic 1999. Revs up at idle, stalls, fluctuates back and forth?

The following existing problem occurs when the outside temperature is below 5 degrees or above 18 degrees.

When starting, it immediately revs up to between 2000 and 3000 rpm, fluctuating. This happens regardless of the temperature.

As with the temperatures mentioned above, the problem becomes different. The car wants to rev but can't, either stalling or barely staying at 300 rpm.

If you manage to drive, the car will jerk when you take your foot off the gas. And turn the gas up and down.

If the engine has warmed up properly, it will have fewer or no problems.

But sometimes when you come off the motorway and have to brake at the traffic lights, it hums very strangely.

It almost always revs up in P and N positions.

My workshop and an electrical specialist don't know what to do either.

What I have already done:

Throttle valve changed twice

Checked if he was drawing air somewhere

All spark plugs replaced

Flange changed

Regularly change oil

Cylinder head cover replaced due to oil leak. (It's been worse since then.)

The automatic transmission shifts very cleanly and smoothly, and the car doesn't cause any problems even at high speeds.

Thanks in advance for any tips