sr20 hesitation - IAC valve?? please help!

i have a 91 180sx - sr20det 115,000km
it is having some hesitaion issues. when i’m just sitting at an idle it hesitates when i rev it. it does this wheter the car is warm or not. i don’t seem to notice anything while i’m driving, just when i’m stopped. i think it could be my Idle Air Control valve. one mechanic suggested cleaning it with throttle body. could that be the problem?? if so is there anyway to take the IAC valve out without taking the intake manifold off??
Thanks
-Derek

bump.