Cold Start Idle Hunting?

[carsontech]

Anyone else have this cold start Idle hunting? Happens in the morning and after a few hours of sitting, no matter the air temperature. Seems to be engine temp dependant.

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[astolt12]

Anyone else have this cold start Idle hunting? Happens in the morning and after a few hours of sitting, no matter the air temperature. Seems to be engine temp dependant.

Mine does this a little, but only going from low to high and then done.

It'll start off at about 1000rpm and then in open loop system kick up to about 1500 for a second and hold then slowly descend down to 650 as the engine warms.

It hasnt articulated up and down yet...car also has some engine troubles. At the 4th Ford Dealer trying to get it fixed right now.

 

[carsontech]

Interesting, thanks for responding.

I've never seen a car do this that didn't have a vacume leak or something else wrong.

Usually a car will start at a higher idle and decend as it warms up. This one starts, goes up, goes down a bit, jumps up a bit, then bounces around a little more, then finally starts decending as it warms up.

 

[carsontech]

I pulled the stock tune off the car to look at with HP Tuners... There are no tables mapped out to show what idle should be at a certain coolant temp, like there is in most other cars. There is only a idle routine (enabled or disabled) with max an minimum idle RPM in gear and in neutral.

Perhaps HP Tuners hasn't mapped out all of the idle tables so far. But it seems there is a more complex algorithm/routine for idle than the cars I'm used to.

 

[Asharus]

is your a/c on? the idle algorithm is definitely complex, from what i gathered in this old article

http://www.mustangandfords.com/parts/m5lp-1003-2011-ford-mustang-gt-50-coyote-engine/viewall.html


The Coyote's tubular headers were a real challenge for cold starts, so Jeff had to use all his knowledge to get them to pass emissions. And then there was everything over 6,000 rpm, a range where Ford calibrators simply haven't gone before. Maintaining precise control up to the Coyote's 7,000-rpm redline was trying. Team members said if it had been any calibrator other than Jeff-a rabid enthusiast himself-they might have been told to limit the new Mustang's rpm and call it a day. We're lucky so many dedicated enthusiasts were on the Coyote team.

 

[carsontech]

AC on or off seems to not matter. Still does the same thing.

 

[carsontech]

Have an appointment at the service department to drop off my car to have them look in to:

-cold start Idle issue
-bad part throttle drivability until warm
-clutch chatter when easing off on clutch and letting car move itself (say I want to idle through traffic or inch forward without using the gas pedle, car vibrates with clutch chatter)
-5.0 badge coming off on passenger side

 

[carsontech]

Car is now at service center for the above issues.

 

[Sayzahr]

Anyone else have this cold start Idle hunting? Happens in the morning and after a few hours of sitting, no matter the air temperature. Seems to be engine temp dependant.

I have an ecoboost auto tran and although the noise is a bit more fan like in mine on a cold start the idle rpm and duration of the noise is almost identical to yours. Like you said only on cold starts and when having sat for a while.

 

[FordService]

Car is now at service center for the above issues.

Let me know if you’d like for me to escalate this for you, carsontech.

I have an ecoboost auto tran and although the noise is a bit more fan like in mine on a cold start the idle rpm and duration of the noise is almost identical to yours. Like you said only on cold starts and when having sat for a while.

Have you addressed this with your dealer, Sayzahr?

Deysha

 

[carsontech]

Let me know if you’d like for me to escalate this for you, carsontech.

Deysha

Thanks Deysha. They finished looking at the car a few hours after I dropped it off. They stated everything I pointed out as functioning as designed.

The assistant service manager stated the other Mustangs on the lot did the same thing and is within spec.

This is regardless of the video proof and experience I have of the other mustangs on the lot showing they don't have the issues mine has.

They did not address the badge issue because I forgot to mention it.


I plan on test driving and getting more video of other GTs and returning the car to the service center again soon for the same issues.

I have no clue how the service department could have tested and diagnosed cold start idle and drivability issues when the engine was still warm.

Deysha, can you provide any advice or assistance for a situation like this? Can you still escalate even though they are done looking at the vehicle?

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