car starts, idles, and drives fine around town. however at highway speeds, 65-75 holding a steady throttle, the car feels like the engine is losing power for a fractions of a second, but repeatedly making it feel like it's studdering. give it more gas or release the gas pedal and issue goes away. it seems MUCH more prevalent when under a load such as going up small (or large) inclines on the highway but not letting it downshift. HELP! no check engine light (and i know it works for other reasons i had previously with misfires)

99 4 speed automatic, 108k. Timing belt and valves were done at 100k, distrubutor, cap, rotor, wires, and plugs were done around then as well. checked timing, new pcv valve, air filter and cleaned the IACV last week (issue was present before that)

what are some easy to check, high probability culprits?! THANKS

 

Are they aftermarket wires? Some aftermarket wires are really shoddy, and even if they work in the first place they don't last very long. Misfiring when heavy throttle is applied at low rpm is almost always spark-related.

 

OEM plugs and wires. Just swapped both out for a new set this morning thinking maybe, but same results...

 

I've had a problem like this before, replace the camshaft position sensor. It often was throttling my acceleration and after replacement, worked for me! No guarantees but just a thought