Shakes or Wobbles problem
2000 Fiat Siena 4 cyl Front Wheel Drive Manual 50000 miles

since past few days now, i have been experiencing jerking in my car especially while shifting gears. on the highway even during driving i tend to feel as if the car is not receiving a steady flow of fuel cause it tends to hesitate & then jerk forward .also the gear shifting is a bit sticky.i would be obliged if u could opine on the same,cause my mechanic is unable to trace the problem.i have changed spark plugs, fuel filter,fuel pump,but to no avail

thx,
dr kaushik khemani