Results 1 to 8 of 8

Thread: 2011 Mustang idle hiccup

  1. #1

    2011 Mustang idle hiccup

    I currently have an "custom" email tune on my car and one of the things that I noticed with it is that whenever I start the car while it's warm it has a bit of a hiccup when I tap the gas. After 2.25 came out I noticed that they had raised the idle from the factory 650 rpm up to 780 rpm. So today I decided to drop the idle back down to 650 and noticed that the hiccup is very pronounced now and even killed it a couple times. I have thought for quite a while that it seemed to be idling high and my guess is that they raised the idle to 780 to help hide this. I've looked between the two tunes and noticed a few differences in the idle related tables and am thinking about just changing all of those tables to match the factory ones. There shouldn't be any issue doing this, right? I wouldn't think that there is but I just wanted to make sure. Is there anything in particular that would make it do this? It acts very much like a carburetor would if it didn't get a corresponding accelerator pump shot when you tap the gas. It only does it in the first 10-15 seconds after start-up then it runs fine.

  2. #2
    Senior Tuner SultanHassanMasTuning's Avatar
    Join Date
    Nov 2009
    Location
    All Around
    Posts
    3,149
    under torque management look at fuel cut torque and spark torque and spark only. sometimes drastic changes there can cause it. whats your fuel trims and mods on the car.
    Follow @MASTUNING visit www.mastuned.com
    Remote Tuning [email protected]
    Contact/Whatsapp +966555366161

  3. #3
    There are no changes in either of those tables.

    The car is a 2011 manual GT. It does have headers with high flow cats and a Boss intake manifold on it.

  4. #4
    Advanced Tuner
    Join Date
    Mar 2014
    Posts
    309
    Quote Originally Posted by Blazin72 View Post
    There are no changes in either of those tables.

    The car is a 2011 manual GT. It does have headers with high flow cats and a Boss intake manifold on it.
    Check your transport delay settings. Some strategies seem to need this adjusted for LT's while other's don't.

  5. #5
    Thanks, I'll take a look at that tonight.

  6. #6
    Quote Originally Posted by wbt View Post
    Check your transport delay settings. Some strategies seem to need this adjusted for LT's while other's don't.
    Is there something I should be looking at in order to determine whether or not a change should be made? How large (or small) of a change should be made at a time?

    There is no difference between the original and aftermarket tunes in any of the O2 transport delay tables.

    To answer another question. I tried logging fuel trims but the scanner didn't seem to record them while the car was driving. The only time I saw any readings is when the car idled. It didn't really make sense. I'll have to try it again.
    Last edited by Blazin72; 08-04-2014 at 09:17 PM.

  7. #7
    Advanced Tuner
    Join Date
    Nov 2007
    Posts
    232
    I had a similar problem with fuel trims a week or so ago. I update 2.24 every other day or so. Haven't had an issue w/ ft's for a while now.
    "I didn't fail, I just found 100 ways to do it wrong." - Benjamin Franklin

  8. #8
    Advanced Tuner
    Join Date
    Mar 2014
    Posts
    309
    Quote Originally Posted by Blazin72 View Post
    Is there something I should be looking at in order to determine whether or not a change should be made? How large (or small) of a change should be made at a time?

    There is no difference between the original and aftermarket tunes in any of the O2 transport delay tables.

    To answer another question. I tried logging fuel trims but the scanner didn't seem to record them while the car was driving. The only time I saw any readings is when the car idled. It didn't really make sense. I'll have to try it again.
    Check out this thread/post regarding transport delay:
    http://www.hptuners.com/forum/showth...l=1#post355145

    What technically should happen is adaptive learning should take over and adjust accordingly. Some strategies work better at this than others. Fuel trims will typically be out of whack and if your MAF transfer is dialed in, this is the other area to check.

    Hope that helps.