Kiato,

How did you mechanic set your timing?? Do you mean he reset the cam timing??? The ignition timing on th 16v is controled by the computer. Moving the distributor won't change a thing. It is relatively easy to see if the cam timing is close by removing the cam cover and bring the first cylinder up to TDC. The marks cam sprockets should line up.

If the fist shop screwed up the cam timing and damaged a valve, that would cause a slight shake at idle. Run a compression and leak down test to see if it is a problem with the motor.

As Brian mentioned, the air idle control valve can gum up. I replaced mine, but it didn't make much of a difference. You could clean it with carb cleaner to see if that helps. If it has high mileage, I would look for a possible vacuum leak.

Tinker