ORIGINAL: Vegas62

hi guys ,( i appologize my english , i'm a german native speaker who is living in usa, vegas)

i'am new to this forum , i bought few weeks ago a 4runner with an blown head gasket , i changed the head gasket and almost everything is working fine .
Except one problem , when the engine is warm and i step on the gaspedal raise up to 25oo rpm , the rpm starts to flactuating every few seconds ( back to 1500 and then back to 2500 ) the idle is perfect .
Does anybody have any ideas what's worng ??? ways to improve gas mileage?


Thanks for you help , take care and god bless you


Al "the bavarian "