Hi Alex,

give me a few minutes, you will get the data.

thanks for your help

hi,

is it that what you need? sorry, i am no car mechanic
If not i can record and plot it again with less PID´s to get an higher resolution.

Click image to enlarge

Click image to enlarge

Thanks for the data, but I didn't wanted statistic data, I was thinking about the parameters evolution during time.
Something like on the picture below, but like I've said, MAP, FRP and RPM.

Click image to enlarge

Hi Alex,

If you need it with a better resolution i will remove the other PIDs from the recording and try it again tomorrow.
Probably we will get smoother curves. I will also have a look at the X axis because the time is not really clear.

Recording was from 28-Aug.-2015 15:57:20.957 to 28-Aug.-2015 16:02:10.656

Click image to enlarge

Click image to enlarge

Indeed, this is what we are looking for, but with a much, much fine resolution.
We are trying to see what's happening during that second of hesitation, so a few samples per second for each parameter will be desirable.
You can log only one parameter at one time in order to obtain maximum resolution.
Then look at it when the hesitation appears and see what's happening with it and if he is the culprit.

Also, I see something strange there....
After a rise in RPM, the fuel rail pressure drops quite much (300 bar) below its value on idle (500 bar) and then slowly recovers. I remember that 300 bar is around the pressure on cranking, on idle being much more....
Of course, it quickly rise when RPM is rising, but I remember that on earlier cars, pre MY2011 - EDC16 ECU, the fuel rail pressure is kept quit high (800-1000 bar) for extended periods of time, even when there is no need, like coasting. Maybe for being there when it's needed?...
In the case of your ECU, EDC17, this could be for lowering consumption and emissions, but I wonder, maybe this could be related to the hesitation?....

That's interesting , I am very curious what will be the conclusion. Good luck

Hi Alex,

thank you very very much for your expertise.

Today i was able to provocate the symptom only two times.
But the juddering was not so hard and the turbo noise was quite less than yesterday.
The juddering appeared at two peaks between 980.

I will write a daily journal:

Click image to enlarge

Click image to enlarge

Click image to enlarge

Yes, a more detailed chart(s) will be better.
In fact we are looking here for a parameter that has a strange, out of the ordinary, deviation when the hesitation appears. Only after that we can start thinking about causes....
We must look for that/those parameter(s).

In theory, a more humid air will contribute to a better burn. So the moist the better.
But there is no way for the engine management to know the air humidity.
So, I don't think there is a connection here. It will be too strange...

Hi Alex,

i will do a test drive again and try to log the exact time when the judder appears.
Then i will create an overview chart and three different charts for the parameters.

I wonder why the LR garages do not do such a deep dive into the problem like you do for this

thanks

alex_pescaru wrote:

In theory, a more humid air will contribute to a better burn. So the moist the better.
But there is no way for the engine management to know the air humidity.
So, I don't think there is a connection here. It will be too strange...

Humid air really only has more water vapour suspended in it. Don't think the actual air composition differs. FL2 TD4 GS 60 reg Facelift - so many issues
2019 DS. Terribly unreliable.
Sold DS for a 2021 Mitsubishi Outlander PHEV. Fingers crossed....
Sold Outlander for a 2014 SD4 SE Tech because I’m mental
Now greatly regret selling the Outlander. MPG of the FL2 is atrocious and so are the fuel bills. Fun though 😎
Couldn’t afford the fuel bills so back to an older Mitsubishi Outlander PHEV. Significantly better than I remembered it to be…

Hi,

i am back from driving. i was not able to clearly reproduce the judder.
only one or two times. but not so hard, so i think it is not good to analyse the data.

i will record again when the judder appears more.
But for example this one was a good shift without noise and judder i have recorded at the end of the test drive.



To help me understanding the engine, does that schema fit to our Freelander engine?

Click image to enlarge

RichP wrote:

Does humid air carry more oxygen, which I would have thought to be a major factor?

ewrfvadffe wrote:

To help me understanding the engine, does that schema fit to our Freelander engine?

ewrfvadffe wrote:

Is it right that the turbo noise is caused when the variable geometry of the turbo opens to drain pressure out?

If it is turbo noise, then maybe. It's hard to tell from distance, behind a computer screen and keyboard...

ewrfvadffe wrote:

Is the variable geometry controlled by the ECU (in case of MY11 a EDC17)?

ewrfvadffe wrote:

Can be the Adaptive Gearbox a reason for that when it learned my slow driving?

ewrfv just a quick question can you hear hissing noise on removal of fuel filler cap ?