Engine & Gearbox Fluctuating Idle

Discussion in '8th Generation (2008-2015) [Acura TSX]' started by Peterbfd, Saturday 12th Sep, 2015.

  1. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
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    Hi All,

    Started 2 days ago and is annoying.

    Idle which is usually about 650 dips to about 500 every 15 seconds or so and then goes back to 650.
    At 650 the engine is silent but at 500 you can feel the vibrations of the engine which is very annoying.

    Any ideas on a fix or the issue ?

    Thanks
     
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  2. Ichiban Founder Staff Team

    England CJ Leeds
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    Did you remove the battery for anything up 30 minutes that will reset the ECM, or did you clean the throttle body?

    Any of these will lead to the above erratic idling you will have to perform a idle learn procedure.
     
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  3. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
    52
    14
    Good call....

    I recently replaced the Front Impact Sensor which resulted in the battery being disconnected.
    This was a little over a week ago and was fine for a few days then it happened.

    Is there a guide for the Idle Lean Procedure on here ?
    I will have a search
     
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  4. Ichiban Founder Staff Team

    England CJ Leeds
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  5. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
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    Brilliant, Thank you.

    I will give this a go tomorrow, fingers crossed it will solve it
     
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  6. Ichiban Founder Staff Team

    England CJ Leeds
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  7. jimjams Club Veteran ★ ★ ★ ★ ★

    United Kingdom nobody zoned
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    Problem is that you need an HDS
     
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  8. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
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    It is my understanding that if you disconnect the battery for a few minutes, this will reset the PCM
    Going to try this out now.
     
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  9. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
    52
    14
    Yep, worked fine, had a little drive and Idle steady each time when stationary

    Thanks again CJ
     
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  10. Ichiban Founder Staff Team

    England CJ Leeds
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    Glad it worked for you mate @jimjams on this occasion as the ECM is already reset, HDS is not be required a simple relearn will fix it.
     
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  11. jimjams Club Veteran ★ ★ ★ ★ ★

    United Kingdom nobody zoned
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    easy to say with hindsight, but the link you give in #4 says " Connect the HDS to the data link connector .... Reset the ECU with the HDS"

    It was the OP who realised that he could reset the engine ECU (again) by disconnecting the battery for 30 minutes, after which the idle learn can then be performed using the rest of the procedure in the link.

    What puzzles me is why he had to do the re-learn procedure, because just disconnecting the battery on its own (for a long period of time) doesn't ordinarily require a re-learn
    e.g. several 7th Generation owners have disconnected the battery at an airport and left it like that for several weeks, come back, and experienced no issues
    (reason for disconnecting at an airport is because some owners report a random parasitic drain which can flatten the battery in under two weeks)
     
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  12. Ichiban Founder Staff Team

    England CJ Leeds
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    The 7th Generation guy have been lucky, or thet don't reliase the idling is erratic as long as the engine runs its fine mentality lol.
     
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  13. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
    52
    14
    Just an update...

    When the blower is turned off, the idle is fine.
    When it is turned on, the idle still fluctuates.

    It does state to turn all electrical items off when doing the procedure which I did.
    Question is, this would teach it to be OK with the blowers off ?
    Thinking of doing it again with the blower on (minimum setting as it is usually always on that setting)
    Would this not teach the idle to OK with the blower on ?

    Simple thinking I know and I might be talking rubbish..
     
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  14. Ichiban Founder Staff Team

    England CJ Leeds
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    So when the blower is on is the auto button lit? Idle relearn has to be done with all electrical items off its states that mate in the guide.
     
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  15. jimjams Club Veteran ★ ★ ★ ★ ★

    United Kingdom nobody zoned
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    and that will include the aircon, not just the blower
     
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  16. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
    52
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    I believe the Auto is not on, Just a single bar showing the blower (air con not on)
    In the past the air con has always made a slight difference to the performance but never the blower.

    I will put a video on of what happens later
     
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  17. Peterbfd Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom Peter Bradford
    52
    14
    Right, problem solved...

    This may have just me being a bit thick.

    When the blower is on, it either states (above the little man) - Air Con On or Air Con Off.
    Yes when it is on, you expect fluctuation as this is the norm.
    When it is on Off, you expect the idle to be fine.

    However when you turn the blower on from by pressing the 'up' button the blowers come on.
    But the area above is blank (does not say Air Con On or Off)

    This result in fluctuation the same with the Air Con On.
    Once it is set to Air Con Off, all is fine.
    A little Odd I thought, is it on or off ? Obviously Blank must mean on as well !

    Therefore I officially now have a car with no problems what so ever which makes a change.
    I even may be able to help others out more and stop asking so many questions :Smile: