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Hi all
Tried searching but could not really find anything...
Anyway, I have a 2010 Passat with 170k miles on the clock. Still going strong except for one thing - at idle the revs fluctuate and the engine shakes.
We have recently replaced all the injectors and tried another fuel pressure rail, which has not cured the problem.
Diagnostic scan shows no fault codes, but we found out that the fuel pressure was not consistent on all cylinders.
Any ideas?
When you fitted the new injectors, did you enter the new IMA codings in the injector tables?
Thanks - yes the IMA codes were entered.
We took it to a VW specialist who tried a few obvious things and made a few suggestions. None seemed to make a difference.
Premium diesel tends to improve things slightly.
Just wondered if there might be any other ideas that were missed.
Cheers
Study the high pressure pump values and other measuring block data.
is their any particular time this starts either cold or warm any black smoke at start up or at running temperature maybe a dribbling injector (faulty) you could check by the ohms reading at each injector 2 pins if you get a reading with a multimeter between 1 of these 2 pins and a reading at theout side body of injector then the injector insulation is faulty (injector gossed) Regards Mickeybo
I think this was probably carried out when it went to the garage. Can this be done with an OBD reader? If so I can borrow one to use at home.Quote:
Originally Posted by Crasher
It happens at all times, from start-up and throughout a journey of any length. It doesn't seem to be affected by engine or ambient temperature.Quote:
Originally Posted by mickeybo
As mentioned, we swapped all the injectors and this did not cure the problem.
Other than the erratic idle, the car drives really well and mpg is consistently good.
I think it's safe to say it is some kind of fueling problem but it doesn't seem to be the injectors.
I am no mechanic - I am just trying to narrow down what else to get changed/checked/swapped.
Thanks!
Only if it will show measuring block data.Quote:
Originally Posted by the surfer
A reader that can display Live Data the VCDS Measuring Block equivalent when the engine is running. Usually such devices have the functionality to read live outputs, voltages, temperatures etc., etc. from the sensors / modules connected to the ECU. Readers that can identify the modules first and foremost otherwise they are not likely to work that well on VAG cars. ODB output is usually limited and a more detailed query level required.
I had the exact same problem with my 58 170PD. Turned out to be the Torsion Value was miles out after previous owner had a Timing Belt change. Took 4 different garages to actually get it right. Once it was within range car idled like a dream.
Unfortunately this is a Common Rail TDI whereas yours would have been a PD TDI and they don’t respond the way a PD does to the cam timing being slightly out.
Thanks everyone for suggestions and advice.
I got some more live data via the OBD scanner. The fault code causing this seems to be P1065 - Fuel pressure regulation control difference.
The pressure rises to around 300 bar and then drops down to below 50 bar at a cycling frequency of probably half a second.
The information that I have indicates a number of possible causes - all of which we have checked other than the high pressure fuel pump.
A replacement HPFP has arrived today and hopefully I can get it fitted next week.
Will update as to how it goes.
Cheers
Before you restart, thoroughly bleed the system by running the in tank pump and if fitted, the electric high pressure fuel pump. Do this for at least a minute.
Many thanks for this advice.Quote:
Originally Posted by Crasher
Can I ask the reason for doing this?
The gears inside the pump run directly on the aluminium and the fuel is the lubricant, when it runs dry the pump can be destroyed in seconds and send aluminium swarf into the injectors which you can’t get out. It is common for the HPFP to fail just after a filter change and CAN indicate the person doing the job did not bleed the system and this process is not optional. If the pump fails and fills the fuel system with swarf, putting the damage right using all genuine parts and main dealer labour comes to over £6k.
Thanks again, Crasher :beerchug:Quote:
Originally Posted by Crasher
I will make sure this process is carried out.
Hopefully doing the job tomorrow. Fingers crossed!
Bad news...
Had the HPFP changed over today.
Problem remains as before.
Little bit stumped...
IF the HPFP had eaten its internals AND the debris has entered the system then just changing the HPFP won’t solve the problem of blocked injectors due to the swarf in the fuel system... this is why HPFP failure is such a disaster.
I’m almost certain this is not the case. The car has been idling rough for a long time and the HPFP hasn’t catastrophically failed. I just assumed that it could be faulty. The car starts and drives perfectly.Quote:
Originally Posted by Crasher
Also the injectors have been changed.
After driving the car briefly this evening, the idling has improved slightly but it’s still not right.
After looking up the fault code (P1065) it seems that there are a few possible causes. Haven’t checked the low pressure pump or the in-tank lift pump yet. It seems unlikely either of these could be the culprit, but I’m not sure.
Someone suggested doing a compression test. I doubt there is a mechanical problem as the engine drives so well. It’s literally just the idle that’s a problem.
We’ve also changed the fuel rail and the sensors at both ends to no avail.
Already spent around a grand trying to get this issue sorted so a little bit reluctant to keep throwing money down the drain unless I know exactly what needs doing.
Hi
Does anyone know if I should have done a software reset after changing the high pressure fuel pump?
Because I didn’t and now I’m wondering if this will make any difference.
This is a long shot in the grand scheme of things but my main guess on this. Check the loom for a rub through. Follow the wiring of the pressure sensor and the regulator which are either side of the fuel rail. Follow the wiring back as far you can with a small mirror so you can see the rear of the loom at all times. You might have to get underneath the front of the car for some of this (keep safety in mind)Quote:
Originally Posted by the surfer
I was just poking around my own car the other weak and saw my loom was out of place digging into a bracket, it reminded me of your fault
No, all you have to do is bleed the system with the electric pump or pumps if it has two.Quote:
Originally Posted by the surfer
I'll have a look at this! Thanks for the suggestion.Quote:
Originally Posted by Roverfan
Thought so - thanks!Quote:
Originally Posted by Crasher
Looks like another trip to the garage!
Don't whatever you do run or even crank over the engine before bleeding the system electrically for at least two minutes.
We done the job a couple of weeks ago and did bleed the system but probably for not as long as 2 minutes.Quote:
Originally Posted by Crasher
Still have same problem as before.
Going to take it back to a different garage as out of ideas now.
Hi - I know this is old now but just wondered if this ever came to a resolution - Your problems sound identical to the issue I now have.
@vheedublyou also start your own thread in the model specific forum and included a full scan with the cars VIN.
Quote:
Originally Posted by Crasher
Hi Crasher and thanks - As its all in context I thought it better to try and speak to the original poster - It would be great anyway to see if there was a resolution to this, there is nothing worse than doing a search, reading through several pages and it goes dead at the end. I dont have a scan anyway, I have just ordered a OBD Eleven which I'm hoping will give me an insight at least on live data - My car is not producing any error codes on a regular OBD tester. My car is a 2009/2010 Tdi 140 CBA Engine Passat....Symptoms identical to this OP
Yes getting feedback from the other chap is good but starting your own thread as well gets more attention from other people.
HiQuote:
Originally Posted by vheedublyou
Yes I did get this resolved. Turns out that the high pressure pump was fine. Just needed a software reset with VAG Com.
It’s been fine since then.
Hi,
Sorry but on what you mean doing a software reset with vcds what did you do?
Asking because i have a similar problem with my 2009 tiguan tdi
Hi man, glad to see a recent post about this issue. I have the exact same problem on my A5 CAHA 2.0 tdi. I've replaced both sensors on the rail and the metering valve but still seeing the pressure bouncing around like mad, car shaking at idle but under load its not too bad.
Any idea what the software reset is, assuming a garage had to do it?
I've got VCDS at home and tried some resetting learned values in the basic controls for fuel pressure/metering but it seems to do nothing (I am using a dodgy copy from a friend...).
I'm hoping now all I need to do is get a proper garage with legit VAGCOM to reset it?!
You will get a better result by posting in the Audi A5 section, include a full VCDS scan including the VIN.
Have anyone resolved the issue? Im having the same problem with my car...