[roni21]

thanks for very much. Once the engine is offed, the vacuum gauge start dropping and before 10 seconds, it is all down to zero. There's no oil in the vacuum reservoir and i still can figure out if there's any leakage. My gears also take longer time to change
++++++++++++++++++++++++++++++++++++++++++++++++++++
Hello.
10 Seconds???
This indicates that you have a vacuum leak.
Most likely the vacuum pump is worn out. And how did you know that there was no engine oil in the receiver? To see this, you need to remove the valve cover and try to drain the oil from the receiver by placing the valve cover vertically so that the receiver fittings look down. Replace the pressure converter, it is responsible for the boost pressure!!!
When the engine is idling, the boost pressure should be approximately equal to atmospheric pressure.
approx. 10xx m.bar

If my post helped you hit the thanks and reputation button. Thank you.

Oh i measured the vacuum pressure from the pipe that connect to the vacuum pump - the valve cover. What you are saying is that i will have to take off the valve cover to verify if there's any leakage. I have changed the boost pressure but still same problem. On a level land the car runs fine until when i push the pedal hard before getting limp mode