The problem was with liquid gas to vapor converter, reducer or what's the name. Car has this LPG addon so that it can drive on LPG fuel. The reducer requires maintenance from time to time, and after re-sealing it the issue was gone.

I suspect it to be related to LPG fuel. When driving in LPG mode, turning off the engine leaves LPG (gas) in the engine (just my thoughts). So when next time starting the engine, it has to get rid of this gas, then pump and pressurize new petrol, then create air-petrol mixture to be able to ignite, ...

My problem started appearing again. I will investigate vacuum, hoses, EGR. I don't smoke but I will need once, to check for vacuum leak

It went away on its own. Sometimes it still happens but I stopped to care.

It's done. They revamped the transmission and did 2 test drives before releasing the car. After I received it I've already driven ~1000km with it, no signs of issues. - Pulley set with chain - repaired ..........723,00 - O/H kit with pistons......................365,32 - Filter internal (received wr...

Are you talking about replacing these balls in this video: https://youtu.be/vlKYNL_wdd8?t=1764
Thank you for this valuable information. I will forward it to them, just to be sure.

I am sending the car to the transmission-service. They told they can for sure repair the transmission, they will replace what will be necessary and clean/renew the rest. They will then drive it for a while, then they open check the transmission again for any new debris or so, to determine whether an...

That is some deep knowledge you seem to have in transmissions. Thank you very much for this info. I however am located in Europe so the logistics is a problem, also parts here are much more expensive than in the US. The transmission-specialized service here estimated the price of parts at about 1500...

So they simply told the transmission is bad, so I have to either pay 11000€ to REPLACE the entire transmission or they can remove the transmission and send it to other nearby service that is specialized in transmissions, to have a look at it. They also made these 2 pictures of the transmission. http...

My "Mileage" is 170000 km, so about 105000 miles. I thought it was unusual for such a simple transmission to fail so early.