New to me 09, idles high, hesitation between shifts.. help

Discussion in '2005+ Mustang GT 4.6L Tech' started by Deezil, Sep 13, 2021.

  1. Laga

    Laga Member

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    After you get the SCT, get it touch with Lito for a tune, and your regrets will disappear. http://www.tudyno.com/
     
  2. Deezil

    Deezil Junior Member

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    Im looking at them right now, my bank account is disappearing also. haha... Appreciate the link!
     
  3. Oliver Vigil

    Oliver Vigil Junior Member

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    I would try swapping your throttle body out. I had this issue not too long ago and turned out to the the Idle Air Control Valve, which is located on the throttle body. What you're describing sounds like this issue exactly. Best of luck!
     
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  4. Deezil

    Deezil Junior Member

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    Ok, Ill see about that also, I wish I knew someone locally with a mustang graveyard to try stuff off! haha.. Thank you!
     
  5. dark steed

    dark steed Resident noob

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    I know the stock tune had the dreaded slow rpm decay. I heard that it was supposed to help with shifting. It made it worse for me. Even the (original, before AM) Bama tune took away the hanging rpm issue.
    Not sure about the high idle…


    Sent from my iPhone using Tapatalk
     
  6. Deezil

    Deezil Junior Member

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    between shifts, the rpm picks up 500 before it goes down, if I let off the gas about 1 second before pushing in the clutch to shift it doesnt do it, strangest thing ever...
     
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  7. Dino Dino Bambino

    Dino Dino Bambino I have a red car

    Age:
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    It's the BBK Blackout CAI:

    https://www.americanmuscle.com/bbk-blackout-cai-0509gt.html

    The aluminum intake tube is quite heavy so make sure there's an airtight seal around the collar between the tube and the throttle body. Otherwise even a small air leak can cause idle issues.
    Since your car came without a handheld tuner, the PO may have installed the CAI and left it either with a stock or an unknown aftermarket tune. Therefore I suggest you do the following:

    1. Buy an SCT X4 tuner. It'll come with various canned tunes including one for the BBK CAI, but a custom tune by a performance shop like Brenspeed would be preferable. They provide the options of 87, 91, and 93 octane tunes.

    2. Ask your nearest Ford stealership to check if the car has an aftermarket tune. If so, you'll need to have the ECU reflashed with a stock tune. If it's already stock, you're good to go.

    3. Upload your preferred BBK CAI tune from the SCT X4 to your ECU. The SCT will store your stock tune thus allowing you to return the ECU to stock at any time.
     
  8. Deezil

    Deezil Junior Member

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    Thanks so much, Ill will do that for sure!
     
  9. Stoenr

    Stoenr forum member

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    RPM hang between shifts is what they do on the stock tune. all i got.
     
  10. Deezil

    Deezil Junior Member

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    Ok, so, some more tinkering last night, I noticed the plug on the PCV on the driver side valve cover was not pushed down all the way, so I locked that into place, no noticeable change in idle speed or between shift rev ups.

    I cleaned the MAF again, really good this time.

    When its idling I can disconnect the MAF and idle speed doesn't really change much either, but when I plug it back in the car dies, then on restart idles high still.

    I was wiggling the plug on the Throttle Body and accidentally pulled it off, then put it back on asap, the car sat to a normal idle speed, I thought, hey, its good! But the gas pedal did nothing, so I shut it down and restarted, and it idled high and no change there either...

    Getting an X4 tuner tonight, so we will see if a different tune will fix this stuff, as I dont know whats on the car currently.
     
  11. Deezil

    Deezil Junior Member

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    Ok, so I got the X4, my car must not have had a tune on it as the x4 let me in, so I set the CAI to the BBK, and checked the idle speed at 760 or whatever it was. Flashed the car, now the idle is normal speed. But it still hangs on RPM between shifts...
    I have a local guy thats going to let me try his factory TB to see what that does in the near future.

    Thanks
     
  12. Deezil

    Deezil Junior Member

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    Looking things over and over, what does your connection at the brake booster look like? Are they all this way? Looks glued or something?
    IMG_4625.jpg
     
  13. msvela448

    msvela448 forum member

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    That's not right... Someone broke it and then smeared silicon or something on it. There's a possible vacuum leak for sure. Below are pictures of a brand new one from an auto parts store. [​IMG][​IMG]

    Sent from my SM-N975U using Tapatalk
     
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  14. Deezil

    Deezil Junior Member

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    Ok, good! Ill get that replaced asap!! Thanks. I was hoping some others would snap a pic of what their car has there too!

    Just called napa, they cant even get that plastic part
     
    Last edited: Sep 17, 2021 at 2:04 PM
  15. GlassTop09

    GlassTop09 Member

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    Go to your Ford dealership & order that part. Costs around 10-12 bucks when I ordered mine. Only place you can get this w\o having to buy the entire BB assembly..................

    Been there, done that.
     
    Deezil likes this.
  16. Deezil

    Deezil Junior Member

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    ok, will do! What did your car do with a broken valve? My brakes work great, so Im not convinced this is the fix all find yet....
     
  17. Stoenr

    Stoenr forum member

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    As I mentioned before, the RPM hang between shifting is normal on the Throttle by Wire. Nature of the beast. It can be corrected with a custom tune.
     
  18. GlassTop09

    GlassTop09 Member

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    Found a vacuum leak in it thru running a smoke leak test back in 1-20 (someone put something hot against it & burnt a VERY small hole in it....was like that when I bought the car but wasn't noticeable until I ran smoke test).

    Ford part# XW4Z-2365-AA
     
  19. Deezil

    Deezil Junior Member

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    ok, thanks, Ive listened to alot of vids and never hear it there, Ill get ahold of lito and pray he can cure it.
     
  20. Juice

    Juice forum member

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    FYI, I get a small amount rpm flare on shifts with the coyote, on the factory tune. From what everyone says, Lito is the man, and very reasonable.

    I broke my vacuum check valve installing the engine, lol. Its a simple one way valve, so any brake checkvalve will work as long as it has the same diameter connections.
     
    Deezil likes this.
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