WOW, snap diagnosis, I think I would want to prove an item is bad before I spend real money to swap it out, that must be a cheap part or a super common problem that should be listed in every forum about this car.
What speed are you traveling, is this a constant speed, accell or decell, under what load, uphill, level, downhill, how bad is the jerking, do you think you may also have a really bad electrical connection loosing power to the entire car, what other items do you notice happening at the same time. Do you feel that the car is fully warmed up, does the problem happen sooner than, well you didn’t say a time frame of minimum driving before it starts to act up.
Lights flicker, fan stops blowing, speedometer drops, tachometer drops, any other diagnostic help you can offer. A vacuum leak to me is at a stop or very slow speeds, once moving at a good pace, vacuum leaks are not so prevelant, but large leaks while driving will not allow the car to idle as a stop. Losing ignition will cause your symptom and of course fuel delivery will not handle a heavy load, fast accel or high speeds, will starve for fuel.
Give more info please.