Vibration and jerking when the accelerator/gas pedal is pushed

Greetings All:

My 2000 Buick Century has a vibration that starts around 50 mph, I have had the tires balanced, new routers, and new brakes put on. The hesitation/jerk when I apply the gas pedal is intermittent and I can't make sence of it.

I s anyone else having this problem I have 56,000 miles on the car.

KM

Hi;

I had a similar problem. It was the transmision hunting, it was cycling between gears as the speed signal was not coming through cleanly. I surfed on it and found that new plugs and wires will solve it. Needless to say I was very sceptical, but it worked.
If it happens when on a slight incline and around 40-50 miles an hour then it is the same problem I had. The engine seemed to run fine, but I guess the wires and plugs degrade just enough to screw up the sensors.

Hope it helps.

Spoonhead