Injectors Flow Correction Readings

[logic28]

Hi guys and gals, first post here,


One of my two Meganes is a 2007 1.5dci Privilege acquired a few months ago but not driven yet as it was showing an intermittent problem with injection.
That now appears to be sorted after several routine maintenance jobs and repairs done including a suspected faulty engine wiring loom.


However as I restarted the car, (being an old dog of Vintage Racing Porsche Developer and driver who knows nothing about modern stuff) I immediately picked up what I would call an unsettled engine between 1000 & 2000 Revs.


It certainly inconspicuously rumbles and vibrates at 1700/1800 and sometimes also at 1200, just like a mechanically internally unbalanced engine, however something in my mind seems to always point at a poor mixture in that range.


So, having already done a compression test, I checked the injectors fuel correction values against engine speed but, not been experienced on these more modern technologies (we used to run all our 911s on Bosch Mechanical Inj.) I can make little sense out of the readings.


I thought that perhaps someone here might be able to throw some light on the subject so I have posted the test results.
For a start, they don?t seem to vary at all after 1000 RPM by sticking at values around 1 steadily ?. ?. is that right ? or Im I getting false readings here ?


While running the test i would have sworn having seen some light greyish-colour smoke, smelling like kerosene ?? possibly a rich mixture ?


Tomorrow I will also check for injectors coding (forgot it today).


I have not had the car on the road for a blast to clear the system as yet cause I didn?t want to pay for a second insurance until this is sorted but perhaps I should have done.

Any comment or suggestion is very much appreciated.

Thanks to all

[rideon]

The image you posted is too small , try editing the message with a bigger one..

[logic28]

Sorry, I have tried but it seems to be the way this forum loads the files... they are 2800 pixels ..... they appear to be fine in other forums.



UPDATE ! ! ... i have managed to save in PDF and it's now much more visible, thanks

[Milicija]

Hi guys and gals, first post here,


One of my two Meganes is a 2007 1.5dci Privilege acquired a few months ago but not driven yet as it was showing an intermittent problem with injection.
That now appears to be sorted after several routine maintenance jobs and repairs done including a suspected faulty engine wiring loom.


However as I restarted the car, (being an old dog of Vintage Racing Porsche Developer and driver who knows nothing about modern stuff) I immediately picked up what I would call an unsettled engine between 1000 & 2000 Revs.


It certainly inconspicuously rumbles and vibrates at 1700/1800 and sometimes also at 1200, just like a mechanically internally unbalanced engine, however something in my mind seems to always point at a poor mixture in that range.


So, having already done a compression test, I checked the injectors fuel correction values against engine speed but, not been experienced on these more modern technologies (we used to run all our 911s on Bosch Mechanical Inj.) I can make little sense out of the readings.


I thought that perhaps someone here might be able to throw some light on the subject so I have posted the test results.
For a start, they don’t seem to vary at all after 1000 RPM by sticking at values around 1 steadily …. …. is that right ? or Im I getting false readings here ?


While running the test i would have sworn having seen some light greyish-colour smoke, smelling like kerosene …… possibly a rich mixture ?


Tomorrow I will also check for injectors coding (forgot it today).


I have not had the car on the road for a blast to clear the system as yet cause I didn’t want to pay for a second insurance until this is sorted but perhaps I should have done.

Any comment or suggestion is very much appreciated.

Thanks to all

Hello Logic28

For me it is hard to explain in English but I will try. These injector correction values are ment to compensate different speeds between different cylinders. The speed in different cylinders can varry because mostly few reasons: the compression in this cylinder is low (not enough bang , than the correction value in this cylinder for this injector is with +, for example 1 mg) or the injector is injecting not enough or more than needed (thank the value should be with -, for example -1mg). I can't see your pictures, but these corrections are useful and are ment to analise on idle. For example, VAG concern vehicles, the correction between -2,5....+2,5 mg, mm3 is considered as not accetable, ECM registeres fault. But as I mentioned, these corrections are ment to analise on idle, you don't know, how the injectors "act" on higher pressure, smaller injection time, etc...

I can see you did a compression test and I know alot of this vehicles with injector problems. My advice would be - take all injectors and send them for a company, which would test them on bench. Sometimes they are "fine" on idle, but on higher fuel pressure they are not working as ment. If removing take all precautions, work clean, when removing injector piping try to not to get any dirt. When fitting - fit all injectors, do all piping, dont connect injector wiring, crank engine for 5-10 sec, then wait, then again (build rail pressure in system that injectors wouldn't "work" dry) and then connect injector wiring and start car. After starting you can rise the idle to 2000 RPM and hold for a minute (it is precaution, these injectors might get "stuck" when get air-work dry).

I don't know if you will understand something or not, hard to explain in English clearly

[rideon]

If you are talking about bosch common rail 'correction' is done on idle and low revs to keep the engine 'smooth running'
OP is complaining about renault 1.5 this is either delphi or siemens 'correction' is displayed and done a little different
This 'sounds' like an injector issue...

It certainly inconspicuously rumbles and vibrates at 1700/1800 and sometimes also at 1200, just like a mechanically internally unbalanced engine, however something in my mind seems to always point at a poor mixture in that range.

The image is a clip capture, if he manages to post a bigger one members here can give him a hint else we need meathead's crystal bowl...

[logic28]

Hello guys ! Thank you for your replies,

Not sure why the image taken as a snapshot on my Macbook Pro doesn't show well here, it's fine when I view it on mine

It even shows fine on F-book here:


https://www.facebook.com/temporacing...type=3&theater


Injection system = SIEMENS VDo K05_01 - G26/04248

This Injection System seem to also only do the correction at idle as, from what I can see from the clip results, they all level off at around +1.00 after 1000 rpm.

[logic28]

Hello Logic28

For me it is hard to explain in English but I will try. These injector correction values are ment to compensate different speeds between different cylinders. The speed in different cylinders can varry because mostly few reasons: the compression in this cylinder is low (not enough bang , than the correction value in this cylinder for this injector is with +, for example 1 mg) or the injector is injecting not enough or more than needed (thank the value should be with -, for example -1mg). I can't see your pictures, but these corrections are useful and are ment to analise on idle. For example, VAG concern vehicles, the correction between -2,5....+2,5 mg, mm3 is considered as not accetable, ECM registeres fault. But as I mentioned, these corrections are ment to analise on idle, you don't know, how the injectors "act" on higher pressure, smaller injection time, etc...

I can see you did a compression test and I know alot of this vehicles with injector problems. My advice would be - take all injectors and send them for a company, which would test them on bench. Sometimes they are "fine" on idle, but on higher fuel pressure they are not working as ment. If removing take all precautions, work clean, when removing injector piping try to not to get any dirt. When fitting - fit all injectors, do all piping, dont connect injector wiring, crank engine for 5-10 sec, then wait, then again (build rail pressure in system that injectors wouldn't "work" dry) and then connect injector wiring and start car. After starting you can rise the idle to 2000 RPM and hold for a minute (it is precaution, these injectors might get "stuck" when get air-work dry).

I don't know if you will understand something or not, hard to explain in English clearly

Hi Milicija,

Everything understood perfectly well, thanks, you made it very clear.
Also thanks for all your advise about clean working environment with which I agree entirely.

The only grey point is in the technicality of quantity injected;
I would have thought that if the compression was lower in one cylinder (therefore lower combustion temperature) the amount of fuel injected would be reduced in order not to leave unburned particles, rather then being increased.


However this does not seem to be my problem as cylinders 1-2-3 are at 23.5bar and no. 4 is at 22.00bar so they are not out by much.


Maybe as you said , the injectors don’t perform correctly at higher speeds but surprisingly it all sounds fine after 1900 rpm…..but this is only stationary with no load and I have to test again on the road before more comments are to be made.
However my other Megane 1.5 does not seem to have this vibration.


If I didn’t know any better I could almost suspect the vibration coming from the dual mass flywheel as I cannot imagine an injector delivering wrong fuel only between 1750 and 1850 rpm, unless a sensor is giving wrong messages to the system at that particular speed for a strange and unknown reason.


So to clarify the CLIP readings, am I to expect corrections only to be reported at Idle speed with this Siemens injection ?


Is there any other way to check values at higher speed without removing the units and having them tested ?


Thanks again

[rideon]

first thing that cross my mind...
Check if injector codes in ecu match the one on the engine...AND are in (the right renault)order cyl 1 at gearbox side..
No backleak test for this since return is pressurized...

[logic28]

first thing that cross my mind...
Check if injector codes in ecu match the one on the engine...AND are in (the right renault)order cyl 1 at gearbox side..
No backleak test for this since return is pressurized...

Hmmmm??. Rideon ?. yes !


I thought of that and guess what ?
When I opened up the injection diagnostic page on clip this is what happened (PDF below)

As you can see by the last line only gives me the injection computer VIN value, unlike my 2003 model which shows the four of them
it does not show me the individual injectors like on my earlier 2003 model (last PDF).


I could do with some help from an Clip Expert here !??..

No backleak test ? I've actually done that .... N 4 was leaking a tad more .... question of few mg otherwise very little return from all