MY 02 Bonneville has the jerks
 

My 02 Bonn; SSEi with 258,000 km; is starting to jerk .I only notice it when the car is lugging in overdrive when going uphills or it works hard like when going into a strong wind.I keep this car in great shape and in the last while have changed trannyfluid and filter,spark plug wires and plugs,maf sensor(old one died few weeks ago) fuel pump,all brake pads and rotors,etc;It doesn't throw any codes,so help would be greatly appreciated.Wife just loves car so please help get her baby running smoothly again!!!!!!

Mine will act funny when the torque converter is locked up and I try to accerlate a little, but what you decribe, sounds like its missing under load. How old are those sparkplugs?

plugs is what i was thinking too. but corrosion on the coil terminals or the icm terminals can feel like that too

Plugs and wires were replaced about 10,000 miles ago,just find it funny nothing flags,wouldn't a cylinder misfire throw a code.When I get a moment I'll clean all the terminals.

You might also want to try running a cleaner through the injectors. Drop half a can of Seafoam into the gas tank the next time you fill. Since you have recently replaced plugs, wires, and fuel pump (fuel filter as well?) the two suspects that come to mind are a bad coil or a sticking injector.

Have you scanned for codes? Just because the CEL is not lit does not mean there aren't any retained DTC's.

i pulled some plugs out of my moms car that the electrode was almost gone, still no code. its always just like you say not running smooth while locked in fourth. my bonnie was the one that had some corrosion starting that made it feel the same

With what I've experienced from my 92 Bonnie, I'm inclined to agree with 2kg4u. Pour some Fuel Injector cleaner in the mix...Injectors can get gooped up and cause a miss.

i'd bet on coil pack or ICM is getting weak.. if it has not been replaced it is way over due

This, but also check the plugs again.

If a coil is on the way out it could have caused a plug to foul as well from not firing at the right volts.