why does my car idle at 2000rpms ? on 1992 Nissan 300ZX

i adjusted the idle down to 700rpms but as soon as i drive it the car idles at 2000 rpms

by in Buffalo, NY on October 10, 2012
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2 answers
ANSWER by , October 11, 2012
ck for vac leak, if you can't find one have a smoke test done and that will find it
ANSWER by , October 11, 2012
yes do check for vaccum leak, the older nissans had issues with idle air control valve and ecm going bad causing to be unable to control idle.