2009 1.5 dci start up problem update

[Tj1325]

Ok then, start up from cold is scary, engine is running rough and at times feels like it wants to stall. Oil, oil filter and fuel filter changed but with no change to the rough morning idling problem.
Greenflag suggested blocked injectors after 'Engine Failure' warning light came up on dash but after a couple of start ups the warning went off.
Thinking of adding some injection cleaner to the diesel next and give it a good blast to see if it does anything, if not, the garage that did the service suggested it may be a fuel rail problem and I was told Scenics have had the same problem.
Can anyone shed some light on this please if anyone's had similar problems and had it sorted, it's desparate times and I don't fancy throwing money at things that don't cure the problem, thanks.

[AlexB]

Use OBD. The message on the dash means that there are fault codes and freeze frames stored. You may also want to have the engine data recorded while replicating the fault, then plot is as diagrams and let an engineer (not a technician) analyse it (or just post it here).

[Tj1325]

So how is the engine data recorded? Will something come up on the OBD coz the garage reckoned that there was nothing coming up. I'm thinking maybe the OBD needs plugging in after a long spell overnight so it gets a reading as the engine is idling tough, what do you reckon Alex?

[AlexB]

Your garage is probably looking for the codes (DTC), because they don't understand the engine data, i.e. live readings of revs, speed, throttle, all sensors, calculated parameters, etc. These are available on OBD and can be plotted with a computer. If you are relying on a garage, then use a different garage. To me it would be easier to plug a £5 ELM327 in OBD, then dump the live data on the disc in the laptop while driving, then plot it with gnuplot or openoffice.

Recording data is a part of OBD standard. There are readers without connection to a laptop or phone, which do not record. ELM327 does it, and can work with a laptop or Android phone. Scanmaster software is good. This is an open standard, so there are many programs and anyone can sketch a script for this.

Yes, you need to record when the problem is manifesting itself.

[Tj1325]

Ok I think I understand, the garages code reader basically reads the faults that are on the dash or that are in the memory and can also wipe error codes but can't recoed data from a live problem, is that right.
So am I thinking that the discs you get with the OBD will record info as it happens if I have a laptop in the car recording it, sorry if I'm sounding dumb but my knowledge of electronics and engine data is zero to be honest.

[AlexB]

Hi Tj1325,

No, I think most garages have an OBD device that supports recording the live data, but many are unable to use this information for diagnosis. So, they are relying on the "bird's brain" in the ECU to do thinking. These engines are very simple. If a garage can't diagnose a problem within, say, an hour of investigation, it means they do not have engineers in staff, only fitters.

I don't know what is included into the discs that come with the reader - they might be the same as on the web, as they are provided for free. New programs are appearing every day, and many of them are open source (properly free). This one seems to have many features included. Search web for more of these.
https://www.scantool.net/obdwiz/#screenshots