TQ Gauge Fluctuating Question
Super F is absolutely correct, don't pull it (the collective) aggressively - why do you? Similarly, go gently with the cyclic - smooth movements will greatly reduce the wear and tear on linkages, mounts and the airframe in general.
Having said that, the problems detailed by both Bell_Flyer and fokkerpilot are broadly similar and, as mentioned by others, the first thing to look at is the N2 rigging (provided the arm on the FCU is making firm contact with the max power stop it's unlikely that N1 rigging is the problem) One important point of N2 rigging is that the arm on the PTG must not touch either stop with the collective full down and beeped down or full up and beeped up. Check that the entire N2 control linkage is free of excessive backlash, replace any defective part/s.
Next, look for will be loose pneumatic lines on the engine, check for tightness and, if necessary, check the flares for cracks. Remember that pipe flares should align properly with the mating fitting - you're allowed to bend the pipe (gently) to ensure proper seating - a misaligned pipe is a strong candidate for cracking at the flare.
Following that, the next step should be to remove, check and clean the P3 filter. Also, as RVDT said, the PTG can get dirty and on some P/N's you can remove the Px and Py bleed orifices for cleaning - this is a very simple procedure but do one at a time to prevent mix-up.
If you find the Px and Py bleed orifices are dirty and the P3 filter requires cleaning and the engine is sometimes slow/difficult to start, then there's a
high probability the FCU start de-rich bellows bleed orifice also requires cleaning. Note that this is only possible on some FCU P/N's - check the MM.