Intake System Abrupt throttle response

Discussion in '7th Generation (2003-2008) [Acura TSX]' started by NottsBiker, Monday 15th Dec, 2014.

  1. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Hi All,

    Not sure if anyone else remembers on here but I was experiencing an annoying issue with my throttle which I had described as being like a bungee chord when you put your foot down (nothing then everything making it jerky).

    Found the culprit for this which was carbon build up in the throttle body. Removed the body and cleaned it thoroughly with some soft scotchbrite and wd40 = snatchy throttle cured.

    Only problem I'm left with now (apart from creaky clutch pedal) is that the smooth acceleration aided by the cleaned throttle body has highlighted the fact that when you reduce the throttle it feels like it closes too harshly and you feel backlash in the drive train. If it was a motorcycle I'd say that the cush drive rubbers were shot and needed replacing.

    Now not knowing a great deal about car mechanics I'd either think its just how the fly by wire system is, or there is another issue maybe clutch related - any ideas guys?

    Thanks - Ben
     
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  2. DeviateDefiant Co-Founder Staff Team

    United Kingdom Leo Northants
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    Glad to hear cleaning the TB sorted out the previous issue, leave a note on your thread just so others know if they stumble across it in the future :Smile:

    As for the sharp deceleration when coming off the throttle, that does sound fairly normal in the lower gears with 1st being the worst. I'm guessing when you pass that "point" you have a slight jerk right?

    The jerk isn't the throttle body actually closing, the engine would be starved of air, it's the throttle control being taken back over by the ECU so it can adjust the amount of air coming in, and not controlled by yourself and the DBW system you mentioned.

    When I first got my '03 it took me a while to get used to using 1st in stop/start traffic without the clutch because of it. Passing that point she'd noticeably "jerk" when starting to decelerate before I put by foot back on the throttle.

    Without driving your car, I would say on the face of it, that it's fairly normal, but it doesn't sound as abrupt as you describe on either of my CL9s.

    If your throttle body was suffering with bad carbon build-up, chances are your intake manifold could be too. Your ECU may be struggling to regulate the air flow. I don't think it's drive-train related at all.
     
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  3. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Replying on my phone here

    Yes it does sound like you have identified the situation based on your own experience which although annoying because it does not fix the issue but very handy to know what it is - thanks!

    Has anyone found an improvement after a remap?
     
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  4. DeviateDefiant Co-Founder Staff Team

    United Kingdom Leo Northants
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    With neither of mine would I consider it a problem, it's a characteristic of the car for me and I just have to feather the throttle better to get around it, I am thinking that you have the problem worse than I do. Interested to hear some other K24 owners take on it.

    The throttle mapping bias is gone on my map which improves the throttle feel greatly (1:1), the slight jerk is still there when you come off it mind. It's certainly more noticeable on my mapped '07 than it was on the '03 in general because of the extra power, though all the other benefits of remapping kinda negate that.

    Y'know, Notts isn't too far away from Northants and I'm down there a lot of the time. You're welcome to come see how mine drives if you like as a point of comparison.
     
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  5. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Cheers for the offer I may take you up on the offer sometime in 2015. Brother in law's father had just got a job with the Mercedes F1 team so I wonder if they could sort it for me....

    Next thing will be to get the annoying creaky clutch pedal fixed. Roll on the warmer weather so I can get it there and fix it. Be bothered that should read!
     
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  6. DeviateDefiant Co-Founder Staff Team

    United Kingdom Leo Northants
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    No worries, just let me know :Smile: I have the annoying clutch pedal squeak to fix as well :Laughing:
     
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  7. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Ta

    Also just sailed through her first MOT in my ownership with no advisories. One happy Honda owner :Smile:
     
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    DeviateDefiant likes this.
  8. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Forgot to ask about cleaning the rest of the inlet manifold.

    If the throttle body was gunked up with carbon (now gone) where else should be cleaned at the same time to ensure it all works as well as it could / should?

    I can't help but think that the fly by wire system is added and extra complication compared to simply running a cable straight to the throttle body ala old skool.
     
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  9. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
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    TBH honest I can't see the inlet manifold being gunked at all. I've taken a fair few of these off and on K24s they are always pretty darn clean.
     
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  10. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    I did think that would be the car, that's why I thought I'd post up another quick q.

    Thanks for your response
     
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  11. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    Case
     
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  12. DeviateDefiant Co-Founder Staff Team

    United Kingdom Leo Northants
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    My reasoning was that if the TB was gunked up, some of that would have gone further along the path and started accumulating on the intake manifold. Have any of the manifolds you've removed @SpeedyGee been on cars with pretty gunked up TBs?
     
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  13. NottsBiker Top Contributor ★ ★ ★ ★ ☆

    Ben Nottingham
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    I'm more used to carbs than FI so am not really sure tbh
     
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  14. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
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    Hmmm TBH ... no they weren't.
     
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