2002 Other Fiat Models Speed

Other Category problem
2002 Other Fiat Models Engine Size unknown Front Wheel Drive Manual 20000 miles

I have a Palio 1.2 ELX. Following are the problem faced, but not always. I have shown service station but they say no problem found.

1. Jerk while driving. Had problem only 1 day.

2. Car stops while shifting gear. But idle is fine. Had problem only 1 day.

3. Speed suddenly increases without pressing the accelearting. Had problem only 1 day.

Any specific thing I should check for.