Toyota corolla 1999 model vibrating when engage

I face the same problem with my CorollaAE100. Without AC & Neutral its smoothly run but when i turn on the AC engine start to vibrate a lot. Vibrations occur only the RPM is 900 with AC, but mostly when i am at the traffic jam in the Drive mode .Once I got up to speed rpm=1000, this problem seemed to go away. My car examined by two mechanics that have found nothing wrong, engine mount is good. One mechanic said it was the timing belt, so I had the timing belt replaced in the last year, Aug 2014. Original Toyata timing belt. Front & Back Engine mounts replaced in Dec 2013, but one is Thailnad & other original one. Also AC cooler was replaced in last year April 2014. Now the meter is 190,000km. Last week i show this to my frinds mechanic & he said my car needs to EFI tune-up. He said he can do this, but he do not have any machines. Last time when i replaced my timing belt my left Shock mount cracked by him. They do not have any good Jacks, normally they put car engine on top of some wheels.