you prolly need to tighten the iacv...

i just did it to mine today cuz i did the coolant bypass mod on the throttle body

take of the iacv (directly below throttle body) by taking off the 4 bolts on the first part of the tb, sliding it out of the bolts so u can get underneath it, removing the 3 bolts holding the iacv onto the throttle body...

then unscrew the plate on the one side of it, unscrew the white thing that is behind the plate, take out the whole valve, take off the plate holding on the spring, turn the spring around and put it back into the iacv housing, put the plate back on the iacv valve backwards to hold the spring when u put it back into the housing where the spring is...

screw the little white plate back on (not all the way just so it tightly seals off the valve) and put everything back how it was...

be careful to get the spring sitting in the little copper plate that will be on the iacv valve, its tricky cause its hard to keep the plate centered... also dont overtighten any of the bolts on the iacv or the tb cuz i broke one of em... just tighten it till its hard to keep turning

hope that helps... my idle was fluctuating between 1000-1500 rpms when the engine was heated up and now it stays steady at 750