idle problems

[leigh 7005]

my vs has started to idle weird first start it ats all good let it idle for about a 40 sec and the revs drop and it shakes like a massive cam then you drive it and its fine then stop at a set of lights for a bit and revs drop and shakes.i havent had much to do with ecotecs but my guess is the co2 sensors or steper motor am i corect? anyone had this problem? and it shows no codes?????????

[accentstencil]

The IAC valve (idle air control) would be a good place to start. Sometimes a good clean of the IAC valve will fix them.

[Cobez]

I had that problem, mine didn't shake that violently when the revs dropped, but i just replaced a split vacuum line about 20 minutes ago, fixed it up fine.