I have a Dec 1999 Toyota Camry Conquest with a V6 3L engine (1MZ-FE), automatic, 135,000km. Sometimes (10-20% of the time), the idle sticks high (900rpm). Most of the time it idles at 700rpm.
This high idle problem happened recently (3 weeks ago). It is not related to AC, engine well warmed up, temperature gauge display normal. Tapping gas padel does not set it back. If the idle is at 700, change from neutral (N) to drive (D) is smooth. If it idles high (900), N to D change gives a forward kick and the idle drops down to
700 (when in D).When it idles high, transission from first gear to second also gives a forward kick.
Firstly, I have suspected the IAC. After extensive searching of the internet, it looks to me that the IAC problem is more to do with low / unstable idle.
Any relevant suggestions about the possible source of problem or solution would be highly appreciated.
Regards,
Sam Yang snipped-for-privacy@csiro.au