Stutter under steady speed

[supreme_style21]

2004 3400 - 81k
When cold, it has an occasional stutter at LIGHT acceleration, generally about up to about 20 mph. It's hit-or-miss as to when it does it.

At any temp, it has an occasional stutter around 32-35 mph and around 60 mph. No external conditions seem to affect it. It does it only when it feels like it. RPM gauge does not flutter or change when it does this. I have no SES/SVS lights and no pending codes.

I'd compare the studder to hitting a strong headwind or hitting a "puddle" in the road after a rain. When it starts doing it, hitting the gas makes the car respond normally.. get back to a steady speed and it starts stuttering again. Again, it only happens once in awhile. Sometimes it cruises along perfectly, other times it starts bucking.

I've changed the plugs and wires (replaced with delco iridiums and delco wires), TPS, fuel filter. Trans fluid I have not changed, but is red and looks normal.

What am I missing?

[[ion] C2]

TPS is what mine was. With a wideband O2 sensor I could see lean spikes occurring. When I monitored the TPS reading it was jaggy, compared to previous data logging where it was always smooth. Once I switched it it was fixed.

[Redog]

Check the ring inside the crank pulley. Mine was bent just a little bit and pulled part of my 24x sensor out o the block. I couldn't go faster than 2000 RPM's (60 MPH) without problems.

Also check for any vacuum and exhaust leaks (at the engine block)

[supreme_style21]

I replaced the TPS first, figured it had a few dead spots in it. But it did no good.
I've got no access to a reader to see live data.

[supreme_style21]

Hate to bump an old topic, but it's still doing this off and on.
I have noticed recently if I'm accelerating moderately and get up to 30-35 and let off the accelerator suddenly, it'll jerk/chug/studder briefly, less than a second. It's tough to explain that feeling. I can't tell if it's a trans thing or an engine prob.
Still at a steady speed 60-80 mph on the interstate, it'll occasionally do the same thing. Rare, but when it happens, it does it pretty bad. Makes me wonder if I'll make it home.
Don't know if the two are related.

[guiguilandry]

Try to clean your maf... who knows...