Minivan mystery

My 2001 pontiac montana is running poorly. It has 100k miles. It bogs down and acts like it is unable to find the power when going up hills. It tends to make the tachometer bounce and the car jerks in a pulse like manner. If the accelerator is pressed enough for the overdrive to kick in it immediately stops jerking and all is well. According to two mechanics there are no codes listed.

When was the last “tune-up” ie spark plugs, wires, air filter and throttle body cleaning?

I too have the same problem with my 2001 Montana…Did you figure out what your problem was??? I too had it scanned and nothing came up. I did have someone tell me it was a sputter probably water in the gas…I don’t agree it’s more of a jerk and the tachometer goes out of control.

I don’t know for sure but I think galant was on to something in regard to plugs, wires, etc. That’s what I’d do first - especially if you know it hasn’t ever been done. If it isn’t the problem, you’ve done something that should be done at this point anyway and you have eliminated one source of the problem.

I was driving a car that had a plug go bad. Over the course of a few days it got steadily worse. But, it got real bad before a cylinder 2 misfire code was registered.