Rough idle when cold

[Capri83RS]

I've already checked the codes multiple times, nothing to report there, but when I start the car and it's cold, it has a really rough idle. I say "idle" and it's up around 1500 to start, and I can watch the tach drop, but it shudders and shakes until it's warm. It also surges when driving, if not completely up to temp. Bone stock 2014 non-PP w/ 18.7k miles.

Anyone else have similar issues or any insight into this? I can get some datalogs, if need be.

 

[SHOdded]

We love datalogs When it's cold, the SHO will act "rougher" than when it is warmed up. That's normal. But it really shouldn't shudder/shake or surge as long as you are not driving it hard. Has this behavior been present since you bought it? Or has it come on with the cooler weather? Any startup or extended rattles under the hood? Changes in fueling habits? What oil/filter are you using?

It's possible there is a vacuum leak somewhere. Check hose clamps for tightness and hoses for cracking. Check for oil in the intake piping and crud accumulation in the intercooler. Clean the MAP sensors with MAF cleaner. Shouldn't be a problem with 2013+, but check the knock sensor wiring for chafing.

 

[Capri83RS]

It's really only started since the temps dropped below 40 consistently, and once it warms up it goes away. Figure the first 5-10 minutes the engine is running. I don't remote start it in the garage at home, so I notice it more as I'm going to work or going somewhere after the car has sat for an appreciable amount of time. I remote start it at work, so it's nice and warm inside when I finally leave, and don't have the issue then.

No rattles that I can hear, I'm using BP 93 (have since I purchased the car 1700 miles ago), and whatever oil/filter Ford put on it before I bought it. Performance wise, it runs great and I clicked off a 13.76 @ 101 last weekend. I probably just need to let it warm up a little more. I'll get a datalog this morning before heading to Cars and Coffee.

 

[Capri83RS]

Attached is the .csv in a zip file, from this morning. This is from Torque Pro. Haven't messed with Forscan to get it to log the pid data yet.

 

[SHOdded]

Looking the file over now. At no time did you go WOT, correct? I see max fuel rail pressure of just under 2,000 psi. The max you will see is around 2,700 psi under WOT.

Here are some custom Torque PIDs (first post) you might want to consider adding & logging:
http://www.ecoboostperformanceforum.com/index.php/topic,3141.0.html

 

[Capri83RS]

That is correct, I did not go WOT. Because rough idle =/= WOT programming Also, it's been raining for three days, and on my 20 mile commute to/from work, there really aren't too many places to go WOT for a few gears. I did another log tonight, however; I tried a different method for recording, and it looks like about every 3 seconds it recorded data, so not happy with that one. It doesn't show much.

I have all the custom torque pids, and based on your recommendation on the ecoboost performance forum, these are the items I'm logging:

[quote author=SHOdded link=topic=5465.msg86968#msg86968 date=1446614117]
Fuel pressure, lambda, O2 sensor voltage at a minimum should be added, I think. If you look at some of the other dashboard layouts (FoMoCoSHO, SHOnUup, LarryLu to name a few), you will get an idea of what other folks are finding useful. Looking at some of the SCT datalogs will give you an idea what to look at for troubleshooting purposes. An example header list (SCT naming conventions) is below:

Time (sec)
ambient air temp F|1|224|10|0
barometric pressure|1|224|73|0
battery voltage|1|224|33|0
charge air cooler temperature|1|224|17|0
engine coolant temp F|1|224|10|0
fuel pump duty cycle|1|224|6|0
fuel pump percentage|1|224|6|0
fuel rear pressure|1|224|59|0
gear commanded|1|224|71|0
intake air temp|1|224|17|0
intake cam position desired|1|224|79|0
knock Sensor|1|224|79|0
lambse bank 1|1|224|97|0
lambse bank 2|1|224|97|0
load|1|224|98|0
load absolute|1|224|98|0
long term fuel trim bank 1|1|224|86|0
long term fuel trim bank 2|1|224|86|0
manifold absolute pressure kPA|1|224|73|0
manifold absolute pressure volts|1|224|33|0
measured afr bank 1|1|224|97|0
measured afr bank 2|1|224|97|0
rpm|1|224|29|0
run time|1|224|56|0
short term fuel trim bank 1|1|224|6|0
short term fuel trim bank 2|1|224|6|0
spark advance|1|224|79|0
spark advance v2|1|224|79|0
throttle angle Actual|1|224|79|0
throttle angle desired|1|224|79|0
throttle position absolute|1|224|6|0
throttle position relative|1|224|6|0
tip prs boost kpa|1|224|73|0
tip prs boost kpa dsd|1|224|73|0
turbo wastegate percentage|1|224|2|0
vehicle speed mph|1|224|74|0
[/quote]

 

[SHOdded]

Yeah, 3 seconds is a bit TOO long That would be one mighty low-revving engine you'd be tracking! Not sure why you had the 0.3 sample interval in the first datalog either, but ok. The more PIDs you track (I think there are 35 or so in the list above), the better OBD scan hardware you will need. The cheap units usually can't keep up and end up fried.

If you think about it, 600 rpm idle = 10 datapoints per second. 6,000 rpm = 100 datapoints per second, if we look at the possible digital sensor datapoints. Not that all the data changes simultaneously of course. But to keep track, you do need good equipment & software.

EDIT: I see TPro's intervals are 0.1, 0.2, 0.25, 0.3, 0.4, 0.5, 0.7, 1, 2, 3, 4, & 5 seconds.

 

[Capri83RS]

I have an OBDLinkLX that I'm using to monitor with. TPro defaults to 1 second intervals, I've been trying different things. .1 showed 10 of the same readings, so I bumped it to .25, but that doesn't appear to be much better. I'm going to try .5 next. This last one I tried, was write to log after a complete scan of all pids, so it's about 3.5 seconds each write. Too long.

If all else fails, I'll go back to 1 second intervals.

What with property taxes this year, and getting a cracked windshield in the SHO on Thanksgiving night, I've pushed getting a tune and better monitoring software further down the pipeline :/ I have to try and make do with what I have.

 

[SHOdded]

Understandable. In any case, it will give you time to confirm all maintenance aspects before you go all in for the performance mods

If the SHO runs fine after getting warmed up, I would recommend a few heavy throttle blasts now & again to help clean out any carbon buildup in the combustion chamber, which can lead to knocking/pinging. This may in turn reduce the shudder/shake you feel at cold idle, as the engine is not continously advancing/retarding timing to combat what it feels are problem conditions.