Why does my Lexus have power surges between 1000 and 2000 rpm? on 1998 Lexus ES300

The problem happens when the engine is warm or at least it is more apparent. Past 2000rpm the surges seem to disappear. It feels as though I am gently pumping the accelerator pedal. It may be more of power loss than a surge, it is difficult to tell.

by in Bemidji, MN on September 19, 2012
2 answers 5 comments
ANSWER by on September 19, 2012
do you have a service eng soon light on?
COMMENT by on September 19, 2012
No.
COMMENT by on September 19, 2012
could be the begining of a misfire that happens only under load. i think i would start by ck'ing for misfires
COMMENT by on September 19, 2012
If I start to accelorate or back off on the acelorator between 1000 and 2000rpm the surges seem to stop. It is only at a steady cruise that the surges happen. Would that be consistant with the beginning of a misfire?
COMMENT by on September 19, 2012
yes very possible
COMMENT by on September 19, 2012
I will pursue that fix. Thank you.
ANSWER by on September 20, 2012
i would check the throttle positon switch