vacuum pressure is too low when idling


i'm using mira avazanto trxx l2s...

my problem is that my vacuum pressure is to low when idling(plus minus 30 atm)..when i turn on the air cond my vacuum become plus minus it normal?
why is this happening?

hope someone will help me with this problem

thank you

vacuum pressure?

what do you mean by vacuum pressure?

do you mean the intake manifold pressure?

if so im not sure what it should be but i know when the air con comes on the vacuum should increase (pressure decrease) because the engine speed increases to run the compressor