1997 Hyundai Tiburon 97 Tib holds back power at 4000 RPM?

Engine Performance problem
1997 Hyundai Tiburon 4 cyl Front Wheel Drive Manual 240000 Kilometers! (Yes I am canadian haha)

My 1997 Hyundai Tiburon accels quickly up to 4000 rpm the it shows hesitation and then continues to accelerate up to 5000 rpm and does this sequence of hesitation over again, but ive experienced that this doesnt always do it so far on the warmer days it will accelerate without hesitation but on colder days it seems to hesitate the most, but yet again I have had it hesitate on warm days aswell, so I figure it may just be a faulty sensor anyone know whats up with it? Im not sure where to start. (Its got all new plugs and wires, new fuel filter, I only run 92 or 93 octane fuel, new fuel filter, new throttle position sensor, Just a few things to try to eliminate)