2001 Pontiac Montana- while accelerating the vehicle jerks or another way to describe it maybe "slipping"

Answer 1

Probably time for a tune-up, spark plugs and wires...arcing ign. wires will make it jerk pretty good...of course, it could be the trans slipping...check the trans level when hot, engine idling in park. Also, check the ign. wires by spraying some water out of a squirt bottle on them while running...if it's bad enough to jerk, you should be able to see/hear a spark going to metal before it reaches the spark plug.

Answer 2

Before you start replacing parts, try to find what it is as parts replacement is expensive and highly inaccurate in fixing problems. If the motor is missing, start by removing both ends of all spark plugs to inspect for corrosion, carbon tracking or holes in the insulation. If this is evident, replace all of the wires, the spark plugs, and even the coil assmeblies as the corrosion cannot be cleaned off as it will come back. If you don't find anything, you shoud do a comp. test to be sure you don't have a bad motor. Try to isolate the cylinder missing which can tell you if you have a valve train problem. If the motor is okay, you might have a transmission slipping or a solenoid becoming intermittent. That will take professional inspection.