16V missing below 2000 RPM

Good afternoon,

I Need some assistance with analyzing a problem. My 16V was running perfectly until I took it into the shop to replace the AC compressor in preparation for my trip to Alaska on next Tuesday (8 Apr). While in the shop I had the timing belt and water pump replaced. When I picked the car up I immediately noticed that the engine, below 2000 RPM would not accelerate normally, coughing and being "herky jerky" (that is a real word) below 2000 rpm. Above it accelerates but does not seem to have the power it had a week ago. Hard to tell but I think it is also not smooth at higher rpm as well.

My first thought is that there was a vacuum leak, however the engine is still pulling about 16 lbs at idle. Now I am thinking that perhaps the cams are not properly aligned.

Any thoughts/ideas will be appreciated. I have told the shop there is a problem and would like to go back with an opinion from the forum. I have only 3 weekdays to fix.

As always, regards, Bill

If I had to guess it would be that the timing belt is off a tooth. Pull the top cover and inspect the location of the cam gear indicators.