hello every one i would like say thanks for this group

i have small problem, my car proton saga iswara 2006
before rpm 1 normal
when i turning air-con staring shaking and rpm 0.5
i try to adjust carburetor by screw-driver by CARBURETOR VACUUM PUMP i make it high 1.5 rpm and truing on air-con it will be 1 rpm after truing off 1.5 ?
i see many car same model engine normal 1 rpm turing on or off air-con it will be same rpm 1.

Thanks again