96 jetta starting problem

[Cthopper]

I have a 96 jetta GLS manual transmission. About 3 weeks ago I had a new compressor and dryer put on at which time I also had the belts changed. Yesterday I drove to another city about 30 miles away. On the interstate I notice some slight jerking. The jerking would not occur while I was accelerating, only when I would let my foot slowly off the gas. I made it to my destination and left the car for about 15 minutes, when I came back to the car it would not start. It turned over fine but would not catch. After about 5 minutes of trying I pressed the accelerator while trying to start it and it caught and started. I drove back home and the jerking seemed more frequent (still not while accelerating) and the car made a strange electrical sound like a ding on the inside. I expected to see a check engine light from the sound, but did not. I got the car home and let it cool down for a couple hours. I later went out to try to start it and it started on the first try, but it was still very hesitant (I did not have to depress the accelerator, though). Does anyone know what my problem could be from this description? I don't know if my new compressor is related, but I thought I would throw the info in just in case. Thanks!
chris

[lite1979]

You probably have a vacuum leak. This means that when the work was done to your car, the intake assembly may have had to be partially removed. Inspect the path air travels between the mass airflow sensor and the throttle body and all air lines that stem from it. Make sure there is no cracks and that all seals are tight.