Intake Manifold Pressure Dilemma

[Giannis]

Now the thing i don't get is that why LOWERING VACUUM in first test resulted in HIGH reading?

I think I need to explain the different names of pressure again.

Your MAP sensor measures absolute pressure. With the engine switched off, the absolute pressure is the barometric pressure. With the engine switched on, the intake pressure has a value that is less than the barometric. The difference between the barometric and the absolute pressure your MAP sensor reads is the vacuum pressure:

VACUUM = BAROMETRIC - MAP READING

Therefore, high MAP reading means lower vacuum and vice versa.

Isn't that correct?