TitusM

I took a closer look and indeed there are multiple letters.... And each letter is in a circle...it seems I was wrong. None of them seem to be listed as compatible with a2 1.2. Soooo this means there might be a difference in pressure and opening temperature. In my case this thing was cracked and air got inside the fuel system so ... maybe someone else can give some extra details?... Why the same part can fit multiple cars. This one seems to have a very different mounting

Do you have some links for the other versions? I paid 10euro for the part aftermarket. Oem is around 50.

The E is not part of the code for the part. And I could not find any valve without a letter. There is only A and B at the end and the mounting is different for the B. The A at the end seems to be the one to go - it was also listed as compatible. The only big difference is the color - the original was white and the new one is black. Maybe the opening temperature is different but this should not be a big difference in the way the car runs. Anyhow this improved only consumption when under load (and fixed the priming issue in my case). After driving a bit is around ~0.5 lower consumption.

Found the issue: the valve on the fuel filter: 057127247A A picture from the internet: - this is the valve in question

Found the issue: the valve on the fuel filter: 057127247A I replaced this AAAND : 1) the idle is not so rough 2)after long idle there is no white smoke on the tail pipe 3)fuel consumption is better - have to make longer runs to confirm (it looks like ~1.5 liters lower for city or hard drives --instead of 6.5L/100km now i've got ~5L/100km) 4)injector correction is much better. Before I've seen 0.5 correction when the engine was warm. Now injection correction is as in picture. From now on I will replace this together with the filter(every 2 years).

Some updates after a long time. The consumption is now around 6.4 l/100km. I was wandering if the knock sensor might have any influence in bad fuel consumption? I understand that for petrol engine at least this is an important part and it does not always raise error. I am programing also some injector repair this summer. Hopefully it will not be that expensive. I noticed that after the car idles for 30 minutes there is some white smoke on the tail pipe if I accelerate. I believe is some unburned fuel(it smells very bad), hopefully is not the head gasket. The car does not seem to suffer from performance issues or any liquid loss. google translate: Einige Updates nach langer Zeit. Der Verbrauch liegt jetzt bei 6,4 l/100km. Ich bin gewandert, ob der Klopfsensor einen Einfluss auf den schlechten Kraftstoffverbrauch haben könnte? Ich verstehe, dass dies zumindest für Benzinmotoren ein wichtiger Teil ist und nicht immer Fehler verursacht. Ich programmiere diesen Sommer auch einige Injektorreparaturen. Hoffentlich wird es nicht so teuer. Mir ist aufgefallen, dass nach 30 Minuten im Leerlauf etwas weißer Rauch am Auspuffrohr entsteht, wenn ich beschleunige. Ich glaube, es ist unverbrannter Kraftstoff (es riecht sehr schlecht), hoffentlich ist es nicht die Zylinderkopfdichtung. Das Auto scheint keine Leistungsprobleme oder Flüssigkeitsverluste zu haben.

Maybe this info from our German friends will help (use chrome and auto translate): https://wiki.a2-freun.de/wiki/index.php/Gelenkwellen

Thanks, There has to be a small filter of some sorts to block large things from entering the pipe system ...but if there is no pump it might just the pipes.

I did the operation above - with "Diesel Purge". The cylinder deviation seems to be the same. After warmup cylinder 3 goes on the plus side. The filter was not black as in video. The return line was pretty clean. What I found out and it's weird is that the trunk pump does not seem to work (but the car starts and works) - isn't there a low pressure fuel pump?. On the diesel line from trunk (in picture below - the closed loop) there is no movement...I expected to have diesel running from trunk and to go in return line...but it does not. The car starts with no problem... but as far as I know there is a small low pressure diesel pump in the trunk that should work. Is the A2 different? @Phoenix A2 , @janihani, @DerWeißeA2 any idea about the above - trunk pump related? Could this influence the fuel consumption or is this normal - the trunk pump is just a "filter" and level sensor?

update: I readjusted the torsion value to be on the plus side. (new rear brake pads, cables and pistons) I noticed that cylinder deviation is better now at idle at least - after torsion value reset. New log: - same run - but all 3 in one ->all 56 km (city and highway ). Non eco...and a bit of race style (sorry i was afraid to go over 180 on the highway because is not straight - no wonder it's limited speed). Consumption 5.3 when home....Better than last time and with Non Eco - this is at least weird. It was a little wormer outside. I will have to redo the same run but with eco on all the way. (i think there will be very little difference in consumption - only in car feel) https://log.tunezilla.com/s/SXzPAZNj Next I will do this and injector gaskets change. Hopefully the injector deviation will be better.

I will go to a certified dealership in town to clean the injectors and replace the o-rings. Hopefully it will not be a very expensive job. A complete rebuild for an injector is around 100euros (completely new parts from bosch). Since it is only cleaning and oring replacement.... The oring kit cost around 15 euro for one injector but I have no idea how much does the work cost (I am a little bit afraid to diy - i might miss some tools). I read some more and it seems that it is possible to have higher consumption because the "holding" o-rings from the injectors are worn and fuels gets loose from return line to the cylinder. Logs to come after injector cleaning and oring replacements (1-2 weeks maybe)

Modified torsion value: Logs here: https://log.tunezilla.com/s/l71v76IY Now is a little bit under 0. (the value is correct on the graph - it is true what you said group 004 field 4 for torsion value)

true... If you speak nice with it it might work as intended and might even take you to the seaside .

I was thinking the same thing with torsion value. I will redo the logs tonight with new torsion value. I did this before the timing belt was changed this summer. It seems that the tools from the mechanic were a little used (but at least is on + side not on -) As I understood it is important to have the value around 0.5, is this right? PD engine like a little bit of+ there. What about injectors? what do you think? is is possible that cylinder 3 injector to have some issues? I am thinking of this because 1.2 is a small engine and maybe tolerance should be smaller? Or this might be corrected after torsion value adjustment? (i have to connect the vcds to the car to see the group for torsion value - i will come back with update on this question) I see torsion value above 3 in graph (if the group is correct as you mentioned):

When I did the test last night I found that the consumption is indeed close to you specification. 80 ->3.x 100/110 ->4.x 130 and above ->4.5 -in my short test. In the graph you can see I was "pushing to the metal" it almost all the time (when i was no afraid of the wet conditions and steep curves). It is a steep uphill on this highway. I have to test it with the golf but I am sure it struggles to accelerate over 150 uphill. Anyhow when i was going uphill on the way home (like the last 4/5 km) the consumption jumped 1L. So from the total of ~ 50km the last 5 km were very demanding. So i tend to believe i am in a special case...when the road itself is "high consumption". Yes. Good catch. The consumption is actually a little bit higher when doing the calculations with full tank->full tank.

Temperature of engine and wheel when I arrived home from the run above: Turbo intake temperature when I arrived home. It was a little hard to get but this was after 5 or 6 minutes of idle. engine temperatures from above. - the circle in the middle is the oil cap. front wheel disc temperature (same on both sides) rear drum temperature (on the other side 17):

yeeees...I do that pretty often. before the long update from this evening i did a reset again.

UPDATE and lots of details: Here are the logs for this evening run. I did a log with advanced measurements. Please tell me what you think. You can find the logs here directly as graph (or csv in attachment): https://log.tunezilla.com/search?part_number=045 906 019 D ->Click "view" on the logs from 13-10-2020 and with lots of groups. LOG-01-011-048-061-07C-105-112-137-152_city_eco.CSVLOG-01-011-048-061-07C-105-112-137-152_NONeco_city.CSVLOG-01-011-048-061-07C-105-112-137-152_external_eco.CSV the log files: 1)city_Eco - in the city with eco mode on 2)external - eco ->out of the city with eco on - and ~15km highway. The highway is not flat - i had a hard time reaching 130 uphill but after that i could reach the 160 limiter. 3)city _non eco -uphill home at the end (when going uphill the consumption jumped from ~4.5 to ~5.3 when I arrived home) Findings so far: -> cylinder deviation: It seems that cylinder 3 is a little off compared to the other 2 - it reached almost 1 at a certain point so it might be good to clean the injectors. Logging a run like this is useful because you can see that injector deviation can vary pretty much. it is very possible that cyl3 injector has issues. I found a max deviation of >0.9 compared to the others. When idle or short run this was not visible. boost vs speed seem fine: boost pressure vs intake temperature vs speed: (it could use better intercooler for uphill - the temperature is quite high at the end)

@clekilein hmm good question. On highway it struggles to reach 130 in eco mode. 160km in eco mode with kickdown or not? The truth is I did not drive one of those before buying it. It was just a dream of mine:)...that now costed me more than the other car (and I still have to fix stuff). I owned a 1.4 fsi Lupo with the same gearbox so I knew what to expect and i had experience with bad actuator and clutch and etc. Right now I want to get out an test it out of the city. I will do a vcds log with speed and consumption and maybe boost. Any hints? What should be the consumption at 130km/h highway speed and how hard should it be to maintain this speed? Hooking up the vcds and going for a drive. I hope it can log such a long way.

@DerWeißeA2 I changed the fuel filter myself:) this summer. It is surely new. I used MAN filter. About the diesel return line - any idea how to test?

Can the diesel return line to the diesel tank be restricted and therefore have a greater consumption? Is this even a valid question?

PCV CCV Valve? Is this breather important in fuel economy? I see some oil around the breather pipe. Does this mean that there is something wrong with it? https://forums.tdiclub.com/index.php?threads/diesels-do-not-have-pcv-valves.10234/ "Just thought I'd mention that the crankcase ventillation systems employed on diesels are not PCV (Positive Crankcase Ventillation) systems. They are Closed Crankcase Ventillation (CCV) systems."

tunezilla has also the groups listed: https://log.tunezilla.com/groups?partNumber=045 906 019 D You can scroll to see all the groups (in case the graph shows something that you do not know where it comes from).

Hi @Phoenix A2, I guess it is not. You would have to use the colors. Try the second one. It is much better. You can "hide" the colors you are not interested (press the color label). The first should do the same but it does not work as well. https://log.tunezilla.com/ example (I use only 3 from all lines - the rest are "cut off" when I press it.). This way you can see only what you are interested in in relation to other graphs: This is the full graph from the above (this is harder to read than the above one):

https://log.tunezilla.com/ This is much better. Zoom works better and loads the file better. "Scroll" zoom works nice too. If you click on a label it does not plot that particular value. It becomes "cut out" and disappears from graph. And it has HISTORY :D:D...awesome. You can see the graphs for other engines like yours. You can access the history by pressing: "Find more logs or groups for the part number 045 906 019 D" https://log.tunezilla.com/search?part_number=045 906 019 D