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High (fast) idle

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Stevewoods, Apr 22, 2015.

  1. Stevewoods

    Stevewoods Senior Member

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    No codes, no lights, but both myself and wife think the ICE idle speed is extremely fast, even when warmed up.

    In the horse and buggy days, I would have picked up a screwdriver and adjusted it with my handy RPM gauge connected to the sparkplug wire and coil wire.

    With the Prius, I don't know where to start. Anyone else experience this, any way to adjust?

    2008 model year, basic Prius about 65K. Oil is fine -- it was changed a week ago by me -- and was doing the idle thing before the oil change and still is doing it. MAF and throttle body look good.
     
    #1 Stevewoods, Apr 22, 2015
  2. bisco

    bisco cookie crumbler

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    how long have you owned it, and when did it start?
     
    #2 bisco, Apr 22, 2015
  3. Stevewoods

    Stevewoods Senior Member

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    OP again...

    Been poking about the World Wide Web and finally (and I have looked for a couple of days), found someone who says they are a Toyota master mechanic and that there is no real way to "adjust" the idle and that such problems are usually caused by a dirty throttle body.

    I did look at that a week ago or so when I changed the oil and put in a new air filter. I did see some black on the edge of the "plate," it did not look too bad to me, but I guess I will try to look up some procedures and see if I can clean that and then see what happens. As long as I am doing that, I guess I will clean the MAF, since I pretty much have to take it out anyway, as far as I know, anyway.....

    I did replace the PCV last weekend, so I guess that is out of the picture.

    I got the beast brand new. It has maybe done this for three months (on the outside six months??)/
     
    #3 Stevewoods, Apr 22, 2015
  4. bisco

    bisco cookie crumbler

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    thanks, hopefully, that's your problem. all the best!(y)
     
    #4 bisco, Apr 22, 2015
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I assume that no warning lights are on such as the check engine light?

    It is true that the engine ECU controls the idle speed and there is no manual adjustment. I agree that you should start by cleaning the throttle body interior as that may help. Remove the air cleaner housing, apply throttle body cleaner to a clean cloth, and use the cloth to scrub the throttle body interior. Rotate the spring-loaded throttle shaft to expose the underside of the throttle plate and clean as much of the plate as you can.

    Regarding the PCV system, make sure the hoses are attached where they should be and that no air is leaking into that system. Make sure that the oil dipstick is securely inserted and the engine oil cap is tight. You do not want any air to be leaking into the engine crankcase as the PCV hoses will route that air into the intake manifold. For that matter, check for any leaks in the air intake system, below the throttle plate.
     
    #5 Patrick Wong, Apr 23, 2015
  6. Fingers04501

    Fingers04501 Junior Member

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    I have a 2008 that is having the same problem, however mine has about 184K on it. I have done all the above recommended things while fixing a different problem it was having over the weekend. Mine still does it though. Did cleaning yours help?
     
    #6 Fingers04501, Jan 19, 2016
  7. Stevewoods

    Stevewoods Senior Member

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    Gosh, it has been so long, I totally forgot about this whole thing, but, yes, cleaning out the TB and the MAF seemed to cure the problem. Of course, since I had the air box off, I also cleaned the snorkel and put in a new air filter, scrubbed out the air box....so, maybe that had something to do with it all, but no issues since then.

    IIRC, Hobbit actually totally removed the snorkel from his Prius....
     
    #7 Stevewoods, Jan 19, 2016
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