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VS slow to return to normal idle after starting

Discussion in 'VR - VS Holden Commodore (1993 - 1997)' started by Cooky80, Sep 9, 2014.

  1. Bowen

    Bowen New Member

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    I had a very similar problem to you almost identical I replaced the iac and tps with no improvement, then after a long list of things trying etc etc there are actually 2 types of iac one for vt onwards one for vs so make sure that's not the issue anyways the issue for me was the 2 units were faulty..... Just cause they're new doesn't mean you can rule them out ;)
     
  2. Cooky80

    Cooky80 New Member

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    Cheers i've got one more hose to check then back to the iac i think could well be faulty or the wrong one as u suggested the lad at my local repco isnt too bright and has given me the wrong part b4
     
  3. Cooky80

    Cooky80 New Member

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    So after a couple of weeks checking for vacuum leaks etc, changing the IAC again, i'm still no closer to a solution. I still get high idle on startup and is slow to drop to normal idle. It was suggested to me to check the base idle and after following procedures on here mine idles around 1400 at the point it should be 450-550. There are no vacuum leaks to be found in hoses after extensive checking of hoses and also taking of hoses 1 at a time and blocking the inlet. Is it possible for a air leak inside the throttle body either around the butterfly or IAC?
     
  4. Bowen

    Bowen New Member

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    Slack in the cable right? Take the tps off and wd40 the whole butterfly mechanism making sure it moves smoothly and returns to its proper location and no small debris or friction stops it? It's free!
     
  5. Cooky80

    Cooky80 New Member

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    yeah throttle body is spotless u could eat of it butterfly moves freely idle screw eased off as far as it will go only reason im thinking air is getting past inside throttle body is after following the base idle reset procedure its idling at 1400 when it should be close to stalling and am not sure if im hearing things that aren't there but when putting my ear close to the throttle body/plenum it sounds like air getting sucked through

    it drives and idles fine just high revs on startup and when changing to drive
     
  6. Cooky80

    Cooky80 New Member

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    im keen to sort this out because a)its driving me nuts and b) it doesnt seem to be very common but after several searches there have been other ppl on here posting the same problem but nobody has ever followed up with a fix
     
  7. Bowen

    Bowen New Member

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    Spray carby cleaner around all gasket surfaces eg throttle body, plenum cover, upper to lower intake manifold while car running and watch for bubbles? Free also :)
     
  8. Cooky80

    Cooky80 New Member

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    Thanks, have already wasted a can of carby cleaner looking for leaks have recently had intake manifold gaskets changed and was doing the same thing before and after
     
  9. Cooky80

    Cooky80 New Member

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    When setting the IAC length to 25mm what point do u measure from the base where it joins to the TB or fro the endof the plastic bit which goes partiallu inside the TB

    Cheers
     
  10. Bowen

    Bowen New Member

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    You shouldn't need to touch it it will self configure
     
  11. Bowen

    Bowen New Member

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    The IAC has over 260 different positions you think your going to get it bang on with a tape? Lol iv never heard of people manually setting it my manual says its self configuring
     
  12. deserthead

    deserthead Well-Known Member

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    I just measured 25mm from the end of the plastic lip.

    I had to pull it out slightly, very gently though.

    You can feel it sit snug in the throttle body, if its extended enough.

    Like I said before, once I sorted the vacuum leak, it started idling properly. If you think theres a crack in your intake pipe, change it out.

    Mine was a small crack in a hose, more than enough to cause me dramas.
     
  13. FXST01

    FXST01 The Grey Man

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    Have you checked that the vacuum ball under the passenger front guard doesn't have a leak?
     
  14. Nut Kracker

    Nut Kracker Donating Member

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    Just make sure you are installing the IAC properly......

    [​IMG]
    [​IMG]
     
    Last edited: Oct 13, 2014

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