johnlo,give us some idea's as to what you have done to try to fix it? First I would look at the plugs,and wires make sure the resistance is not to high in the wires,but the fact that it smooths out when warm,makes me think of air leeks,(vacuum) the best thing is to do is a smoke test,find the leek,check the idle air lines they get hard with age and are not good at sealing if not pliable. It seems that you are pulling to much air,Though you m might also need to look at the EHA and the on off ratio,If you are not having a search problem at return to idle (deceleration) then the potentiometer is probably not bad.Well try some of that for starters,JNT