I removed black part (it is on ign coil) and plugged holes. Engine ran good!!!
I installed it back and engine shakes again.
Is that PCV valve?
Who replaced it?
I guess, I'll go to junk yard to get it
Even though they changed the location of that valve, it's purpose and function stayed the same. It's part of the PCV system. During vacuum operation, this path is where fresh air is allowed to enter the crank case. During boost operation the direction of flow through that path reverses and crank case gasses pass towards the turbo intake pipe.
I'm guessing you have a problem throwing off your fuel mixture and blocking that path richens things up a bit causing the idle to get smoother. Scan for codes. Inspect for broken/cracked/disconnected vacuum hoses. Do a boost-leak-test to find hidden leaks in the intake system. Check the PCV metering valve under the intake manifold to be sure it's healthy. Check MAF and O2 sensor function. Check Group 32 fuel trim data.
Blocking that path isn't something you want to do as a long-term fix. With a sludge prone engine you want the PCV system fully operational.
There should be vacuum restrictor, orifice. Where is it? I think, you told me, it was not a regulator valve. I have strong flow from air box directly to intake manifold.
If regulator replacement doesn't help, I 'll have to make some restrictor