[Yozh]

I'm posting this for a friend with a 335d that needs help. Tonight, we have collected some data from TestO.

I'll let him chime in with more details and clarifications, but I'll provide what I know. 2009 335d with about 140K miles. Deleted and tuned, BPC, stage 3. New vacuum lines, pressure converters, O2 sensor, MAF, MAP. EMP and IAT sensors are old. Has a bit of CBU, injectors original, as is the rest of the fueling system. Fuel filter changed about 10K miles. Ambient temperatures are above freezing, just to eliminate fuel gelling. The issue does not seem to be related to a specific tank of fuel. The issue also does not seem to be related to any specific modification, but an ATM intake has been installed recently and I do not like how the MAF connector been squeezed in. May be he can post a picture. Also, he recently did his headlights with halos etc. but I do not think he could have damaged any wiring related to engine control there. May be rats? He's got some exhaust leaks (long story), but they seem to be post EMP and O2 sensors. No DTCs except for some odd burnt light bulbs. I asked him to check with BPC if DTCs have been enabled or disabled. We did some testing in ISTA but so far nothing came up.

I'll let him post for how long these symptoms been around, when they started and if it was sudden or gradual. But basically, no power, runs rough, sounds like a Suby or as it it runs on three cylinders, fluctuating idle. The benefit is now he drives like a grandma and can avoid further traffic infractions,

Here is some data. Having familiarity with TestO helps. Data values presented in a graph is not always relative, please look at actual data values in the top left corner box to see for a given place chosen on graph (black vertical line).

First a look at RPM. I've highlighted the strange fluctuating spots. And this is evidenced by a bouncing needle.


Or here is a snapshot at idle:


Further images and data will be against RPM (yellow) in the same spot of about 2900rpm.

Rail Pressure actual vs. expected. Generally tracks ok, but not perfect. In my experience, it usually tracks bang on. Also, has this strange fluctuating mode. And interesting that it's also evident in the expected value.


Air Mass actual vs. expected. This one is a strange one. The fluctuations are present in the actual value, not the expected value. Actual and expected are very much out of line and basically do not follow. Also, interesting that expected spikes up on shift.


Boost actual vs. expected. This one is weak based on demand. Actual loosely follows expected and expected, interestingly also has this strange fluctuating pattern to it, but not on coasting. On coasting completely flat.


Boost vs. Exhaust Pressure. Boost follows EMP, very far off in terms of ratio. This was a light drive at no more than 25mph. EMP has this strange frequency to it.


Here is a wider picture of boost and EMP parameters. May be busy looking.


Same for Air Mass:


Same for Rail Pressure:


In conclusion, I would love to hear your ideas. What is the cause of this? I would like to start from MAF and see if may be there is a short in a connector or it may be had been damaged. I, unfortunately, did not pull MAF split data for intake temp, vs air measurement. Also, could this be an injector? May be a simple accel.pedal has failed?

Sorry for the long one and thanks for your time. Aman please come in...

[Mrdeezy]

Mr Yozh, You have always been so generous and helpful to everyone here over the years. I hope you find your answer.

Personally, I would visually inspect everything on top and underneath on a lift all wiring, the harnesses and leaks. I am shocked no limp or cel has popped up. I feel like the tunes make the cars difficult to diagnose. I have sometime turned to the Bmw diesel training pdf’s and learned some crazy stuff, just to remember that I have no clue what the tuner has done with the cars dde. I hope you get this sorted. ����

[robnitro]

Can you check smooth running control in ista/rheingold? Rough idle makes me think of injector balance issues.

The emp/boost ratio will look high at low loads because there is not much fueling, lower exhaust flow, which is counteracted with exhaust pressure to get the target boost request. On a tdi vnt it would close the vanes to achieve the same effect. Without egr, the turbo works a bit harder at low loads to achieve the same pressure

[ninja_zx11]

How do injector balancing values look like in ISTA?That's the problem with tuned DDE that it gets harder to diagnose due to tuners wiping off most of the error codes.
As we have a cable now available to re-tune the DDE without taking it apart,you can try going stock and fix the problem then re-tune again via OBD.Just a thought.

[TDIwyse]

I don't like how "noisey" the measured parameters look... Makes me wonder if there's some electrical noise/isolation issues?

Also, I'm not used to seeing the EMP below the Boost. Not sure I've ever measured that on my configuration.

Found an older log as a quick check to show EMP vs Boost, and also compare the noise of the measured parameters.

Not sure what's going on there Yozh.

[robnitro]

Originally Posted by ninja_zx11

How do injector balancing values look like in ISTA?That's the problem with tuned DDE that it gets harder to diagnose due to tuners wiping off most of the error codes.
As we have a cable now available to re-tune the DDE without taking it apart,you can try going stock and fix the problem then re-tune again via OBD.Just a thought.

Its under troubleshooting ( depending on version of ista). You will see + or - values of each cylinder. They should be between -2.00 and +2.00. A bad injector would show up as a value very different than the others. To make it a more intensive test switch on electrical loads and see if the values change a lot.

[ninja_zx11]

Originally Posted by robnitro

Its under troubleshooting ( depending on version of ista). You will see + or - values of each cylinder. They should be between -2.00 and +2.00. A bad injector would show up as a value very different than the others. To make it a more intensive test switch on electrical loads and see if the values change a lot.

I think we responded almost at the same time by asking same question to OP.
I was also trying to ask Yosh that how the injector values look on his friends's car.Best it to drive under full load and then check the values.On one of my friend's car,injector values were with in the limits while idling but as soon as engine was put under load,values were changing drastically and throwing smooth running error code.He then used double dose of powerservice diesel Kleen for 2-3 tanks,which surprisingly fixed his issue.

[atwal187]

Thank for your help taras . The issue started about a month ago, I installed XHP flash around the same time so I thought that caused the issue but that was not it. I would go WOT or even 70% and the car would just shake badly , like a semi truck just hit me. I stopped giving it excess acceleration . Even sometimes when I would be around 2k I would accelerate enough to cut someone off but not enough power to downshift . Then the problem Would happen here and there . One day I did the same Thing around 65 MPH and then it just kept shaking after that . The rpm needle does not smoothly go up , kind of bounces up and down while going up. As for the exhaust it kind of lopes , when it never did that . I installed the ATM intake a few weeks back but it happened before that also. Maybe because I was rough with the MAF ? could be , figment was tight. No power at all, and shakes very bad at around 1700-1900 RPM, 2k prior is much less shaking

[Owen81]

Are you sure you can rule out transmission issues? I've never experienced it personally but from the stories I've heard, torque converter issues can manifest this way, with the DDE cutting power erratically.

Have you tried swapping MAFs with Yozh? That would be a quick test to rule that out at least

[atwal187]

Have not swapped MAF's but I am going to be trying to
Switch over to the stock airbox. Hopefully I will be able to do that then

[Yozh]

The crazy theory I would like Aman to try is to disconnect his newly installed halos and demon eyes that each had a Bluetooth controller. Given the fact that the whole system is affected it’s a possible interference. Also, check grounds. If you have messed or missed a ground or it’s poor then it could have system feedback. After that we need to look at an alternator. A failing one can send all kinds of frequency through the system and battery will not filter it out.

[da_trem]

Originally Posted by Yozh

But basically, no power, runs rough, sounds like a Suby or as it it runs on three cylinders, fluctuating idle

I had a misfiring problem last year. It appeared almost instantly, 2 injectors dying at the same time.

I diagnose them measuring there resistance. Should've been 180k-200k ohms. They were well below that.

My 2 cents

[robnitro]

Yeah, on my x5 2 injectors started to go bad due to water leaking from the crap tastic partitions and it was intermittent until it started to stall. No codes until it was stalling...

Read each pin to ground to find the offending injectors. My bad ones were 500 ohm to ground and 5k.

[JOHNNYBRAVO1]

I definitely would say Injectors. YOZH, helped me big time on my issue a while back. At the time I had 85,000. I, just finished completing my CBU and getting my DDE back from BPC and completing the Profi exhaust. I couldn't wait to feel the difference from stock to tune 2.5 with meth. Started it up and drove it around the block and it smoked soooooo bad when getting on it. Started checking my work and couldn't find anything wrong- no codes and ISTA couldn't find a thing. I decided to dive in an pull out the last rear injector and dame she was a bitch. There was water stains and rust around the injector and when pulled it was soaked with soot/tar. Pulled the next 3- same issue. My car came from Cali and had really bad CBU. Replaced all 6 injectors from Sprinter supply, it was very exspensive. Installed and registered the new injectors and she woke up. Now it was night and day. Since it was shitty weather in NY and on the lift, I said screw it . I replaced all actuators/maf/map/ motor mounts/electric boxs/change over valves/hoses/seals/gaskets. Then BPC3. Cars been great now for 30,000 + i did just order a DAYCO PB1689N harmonic balancer. I've been told that what diesel guys in Germany are switching too. I'm not messing with FD.