Rpm idling up and down when a/c is on..never did this before

[YoungxNutkase]

Hey my car rpm been going up and down and the engine sound like it has a cold start when the A/c is on...did it today for the first time..currently my a/c is not working but it never did this before...i turn on the a/c when its cool outside so i dont have to open the window (even when the a.c dont work) so i can get cool air from outside sucked in the car so it dont get too hot for my daughter ( she gets hot easy when sleeping)

what could cause this? is it from the a/c not working..if so then why cause it never did this before even since its been down

 

[jwong512]

Sounds like your IACV is clogged. Even though your a/c wasn't used often, it is possible for it to clog up. Just look up the DIY, clean it, and your problem should go away. If that doesn't fix it, it's possible you have a vacuum leak somewhere.