My car is Jetta 2002, the engine automatically shut down when I stopped at traffic lights. I shut down my car and managed to restart my car right after.

First things first is it automatic? if sow what would u meen by jump when stopped . u stop at traffic sign then it moves forward or the engines revs jump when going down to ideal . plse advise

Ther is a problem with some computers in that they shut down the engine for no apparent reason. This problem hounded Kia owners as the engine just stopped at lights but restarted with no problems. Check for any fault codes and check for circuit problems with alternator as some cpu's get their power directly from the alternator and it has to be full voltage or they sense a power failure and shut down.

Replace Fuel Pump .

Engine stalls or RPM fluctuates at idle.

This problem is commonly caused by a dirty automatic idle speed control valve and throttle valve but always run a OBD2 fault code as well as the cleaning procedure. Buy a can of throttle valve cleaner (do not use carburetor spray cleaner!) from NAPA or Carquest (made by CRC chemicals) and spray it into the air intake while the engine is running, use up about 1/2 the can, engine will try to stall hold the speed up, shut it down and let it soak for 30 minutes, restart and blow out the remaining fluid, shut it down and disconnect the negative battery cable for 5 Min's to reset the base idle control

Could be the filter or carbon build up, which is common on the mk4 1.9 tdi's. These engines need to be driven 'briskly' to stop low quality NA diesel fuel from cloggin up the engine.

Look in the owners manual for the explaination of the "dripping cannister" icon. May be low oil or water symbol.

keep driving probally a plug wire missed fired set off sensor upon arrival shut off and restart if this dont fix take to nearest part store they read codes for dree

Check
1)thermostat and also that the electric fan is kicking in when it gets above normal temp
2)blocked radiator
3)worn water pump (more so from electrolysis, ie not using the right antifreeze)

If the car is having trouble maintaining idle (the tach dips and car dies) the common causes are the idle control valve and camshaft position sensors. The cam sensors failing will be indicated by a check engine light.

The ICV can removed and cleaned with good results (I think there is a write up on bimmerfest) or purchased new for about $100.

While you are in there check the intake boot that is Y shaped for cracks, it's prone to fail and will mess up your idle too.

read up on the major forums and you'll get more info

A reason for hard shifting could be a problem with many things with various degrees of seriousness. It could be your ATF( automatic transmission fluid) is low or broken down and old. This would cause the hardness and the reason for stop and go traffic effecting it. Another possibility is your transmission is just shot, and the timing gears inside are worn and not properly shifting at the correct RPM causing a **** during shifting.

Some possibilties, not all!

~Lucas