i baught a 2000 jetta 2.0 5 spd to commute to school. it started acting up this past week. the car will start the idle rough, go to revit up around 2000 rpms it dies but if you mat it it will rev up to red line then let off it will die, then sometimes will idle and come out of it then start doing it again.

 

Mass air flow sensor prehaps?

 

Sounds like its not getting the right air to fuel ratio. When you rev high you force the air and fuel together and it prolly sounds fine, but when you let off it loses all the forced air/fuel and bogs down. I would start with a new air and fuel filter, if that doesnt help, i would go to plugs and wires cause you could have a spark problem. Make sure you get NGK plugs!

 

NGK or Bosch Platinum with multiple negative electrodes. for some reason these cars are VERY picky about spark plugs.

The Mass Airflow Sensor is a notorious problem on VW's and will cause the problem you are having. DO NOT get an aftermarket one!!! I did and it worked for almost a wholw week! The I found out that all the aftermarket ones are re-manufactured and might work for a year, might not work at all. The VW unit is not too expensive.