Revs Counter And Engine Vibration
 

When my car is idling it is perpetually between 5 and 7 on the rev counter . But problems start when i put on the A/C , my car suddenly starts 'shivering' and the engine starts vibrating violently sometimes switching off and then i have to start the engine again keeping my foot slightly on the gas pedal to keep it running which takes the revs to like 10.

My question: is there a way to adjust the engine to make it idle at about 10 so that the shivering can stop , i dont mind if it results into a little increase in fuel consumption (well as a layman i think that is what might happen:D :D :D )

Pls this is urgent as it has turned into an embarrassment--chk this , the other day i was taking my fiancee for a spin and right in front of her friends the engine conked out immediately i put on the A/C 4 times!

cheers guys