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Rough Engine Idle

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by unmesh59, May 12, 2013.

  1. unmesh59

    unmesh59 Junior Member

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    2016 Prius
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    Two
    My 2007 Prius has 127K miles on it and is idling rough, especially noticeable when the car isn't moving.

    Based on various threads here, and not necessarily to address this symptom, I've changed the 12V batteries, spark plugs and used cleaner on the throttle body. Car acceleration has improved but fuel economy and the rough idling remain unchanged.

    I have an ELM327 and the Torque Pro app and the car is throwing off no codes.

    What next? Techron cleaner?

    Thanks.
     
    #1 unmesh59, May 12, 2013
  2. RAL

    RAL Member

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    How long does it take you to burn the fuel in your tank....a week, 5 weeks......? You may have the ethanol blues. If you burn through your gas fairly quickly you will likely not have much trouble but ethanol does not store well AT
    ALL. It starts separating and breaking down MUCH sooner than ethanol free fuel plus if your tank sits half empty for long, much worse in humid climates, it will draw moisture out of the air compounding the fuel problems. I would run some Techron through you might luck out. If you don't burn through your fuel very quickly it would be wise to use ethanol free fuel. If that is not an option I would add some fuel stabilizer that is made to use in ethanol.

    RAL
     
    #2 RAL, May 12, 2013
  3. nh7o

    nh7o Off grid since 1980

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    I wonder about the ethanol storage problem with the Gen II, as it has a bladder tank and there is much less mixing with air. Maybe that bladder is good for something.

    To the OP, some have recommended changing the PCV valve, but I do not recall hearing from someone that said it made any difference in the Gen II.
     
    #3 nh7o, May 12, 2013
  4. unmesh59

    unmesh59 Junior Member

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    We're filling it no later than every 2 weeks. Nevertheless, I will watch out for ethanol in gasoline as a possible factor.

    O'Reilly Auto is running a BOGO promotion on Techron and I bought some. As luck would have it, it was right after a fill up so I will have to wait until the tank is near empty before using it as per instructions on the bottle.
     
    #4 unmesh59, May 12, 2013
  5. unmesh59

    unmesh59 Junior Member

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    Two
    Ethanol free gasoline seems to be non-existent in California. However, the engine seems to be running better after two bottles of Techron though it might be a placebo effect on me!
     
    #5 unmesh59, May 25, 2013
  6. richard schumacher

    richard schumacher shortbus driver

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    You're in luck. In the Bay area you can take it to Luscious Garage for an accurate diagnosis. Without a diagnosis you're just guessing and throwing money at it.
     
    #6 richard schumacher, May 27, 2013
  7. Rich12

    Rich12 Member

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    #7 Rich12, May 27, 2013
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