Jettas are notorious for a lot of minor engine problems, and the part that causes the majority of these minor malfunctions is partly caused by the Distributor Cap. It is a simple fix and you will be surprised by how much better your car will run, or even start up with this small fix. Make sure your engine is not hot when you perform this fix. Open the hood of the car and locate the Distributor and then follow this video. As for the idle try giving the timing a little twist in either direction . it is a wire cord that is attached to the gas pedal, when you press the gas it pulls the arm of this lever like part. on it there is a small screw, with motor running, get a screwdriver, and with it, gently move the screw in either direction until the car is idling at the strength/ speed that feels right to you https://www.youtube.com/watchv=ticvd7ZKc...

YOU CAN FOLLOW THE DIRECTIONS HERE ALSO ATTACHED IS A VIDEO ON HOW TO REPLACE OR FIX THE SWITCH https://www.youtube.com/results?search_q...