RPM/ Power Fluctuation under load

[HDDaveK]

I have a 99 Grand Prix GT with 186k. I get an engine fluctuation (1900-2300rpm) when its under a load such as trying to increase acceleration from a steady cruising speed. The occurs at 1900-2100 rpm & a speed of about 55mph. It takes an increase of the gas pedal, to make it stop going up & down (tach needle) of approx. 2600-2800 rpm & a speed of approx 65 mph or getting on a level road which eliminates the load/ drag on the engine. Could this be a MAS/MAF problem?

[Bio248]

sounds like a TCC lockup issue. let off the gas completely to unlock the TC, then ease back into it and it shouldnt do it.

[01gpgt01]

x2 on lock up issue

[HDDaveK]

Is there a way to fix the problem permanently if it is a TC problem? I push the TC button on the dash to turn off the TC and it doesn't change.

[FoSHO99]

Torque Converter
Traction Control

It sounds like a problem with your torque converter, which is between the engine and the transmission.

[gtpinsc]

torque converter clutch solenoid can be goin out... get it scanned for codes.

[whitehead]

Yea i get the same problem on my 00 GT. But it only happens occasionally. I usually just push the gas down until all of a sudden im slammed into my seat from all my horses letting go . But really the only way to make it stop sputtering is by giving some gas until it does a small "jump" of acceleration.

[SlowNA06]

Vacuum leak or clogged valve body? Vacuum leak is cheaper to fix, so trace all your lines. A scan would help with this... they're free from auto stores.