[MatrixE93]

The car:
2009 335i 6MT, 31K miles, stock other than I had installed Cobb AP Stage 1 for a few hundred miles with NO problems car felt amazing, uninstalled it after I started getting this 29DC code. The previous owner was running Cobb AP Stage 2 with FMIC, down pipes, DCI and BOV. The HPFP was replaced twice, at 2K miles and 15K miles.

Acceleration is jerky with anything more than extremely light throttle, gets more pronounced under heavier load and will throw code 29DC: goes into limp mode as soon as RPM reaches 3K-4K (even lower rpm when going up steep hills). I replaced all 6 ignition coils and spark plugs with Bosch OEM. Intake valves were walnut shell blasted and are spotless. However, the same symptoms remained with no improvement so I took it to BMW for diagnosis.

BMW "diagnosis plan" recommended all 6 fuel injectors be replaced. This recommendation was based on 2 facts. Fact 1) the injectors were original part # 13537585261-06, and fact 2) there were historic misfire codes stored in the DME on cylinders 4,5 and 6. I could not stomach the $1720 quoted to replace all 6 injectors based only on those 2 facts, mainly because I am not receiving any misfire codes currently and I find it unlikely that all 6 would fail simultaneously.

I mailed my injectors to Heath at Injector Doc where he ultrasonically cleaned them, tested the flow rate and spray pattern of each injector. He provided an excellent report and it was determined that injectors #2,3, and 6 were bad.

I re-installed the 3 injectors that tested good (#1,4,5) into bank 2 cylinders #4, #5, and #6. I then purchased 3 brand new injectors (part #13537585261-12 aka
13538616079) and installed them in bank 1, cylinders #1,#2 and #3. I coded the injector adaptation values into the DME, so the injector configuration is now:

Cyl1: 13537585261-12 575230
Cyl2: 13537585261-12 573224
Cyl3: 13537585261-12 574255
Cyl4: 13537585261-06 573217
Cyl5: 13537585261-06 590221
Cyl6: 13537585261-06 576195


So after all of this work, there has been NO change in the original symptoms . The idle is much smoother, but the jerky acceleration and going into limp mode remain. The only code I am getting is the same as always, 29DC cylinder injection shutdown. I am now satisfied that the injectors are NOT the cause. Will BMW be satisfied and investigate other causes? They didn't want to test the HPFP or anything else until I replaced all the injectors and now I'm sure if I go back they will force me to replace the 3 old style injectors in bank 2 with new ones as well. I've checked for broken vacuum lines and I am running out of ideas. Please if anyone has suggestions!!!


I've seen several posts that BMW says the new style (revision 11 and higher) and old style injectors cannot be mixed in the same engine, but I haven't found an official BMW service bulletin with this information. I've also read that they CAN be mixed, as long as it's not in the same bank. I came across this post on the german B000st forum where user vasillalov has 1 new style injector running in an engine with old style injectors and reports NO problems. Do you think it'll be possible to get the dealer to ignore the injectors and look elsewhere?

[N3m3sis]

Did you do new injector decouplers when you replaced the injectors?

[Ingeniator]

Have you checked for boost leaks also it could be a bad throttle body. Try grabbing a log with the cobb that will tell us a lot of the info that is needed to diagnose this. Once you have logged upload it to datazap.me. Also post any mods you have.

[shawntech]

I did some searching, looks like 29DC is consistant with LPFP, check the HPA should be around 5000 at all times, for reference at warm idle my car runs 50000hpa HPFP/5000hpa LPFP

[MatrixE93]

Originally Posted by N3m3sis

Did you do new injector decouplers when you replaced the injectors?

Yes I did install new decouplers

[MatrixE93]

Originally Posted by Ingeniator

Have you checked for boost leaks also it could be a bad throttle body. Try grabbing a log with the cobb that will tell us a lot of the info that is needed to diagnose this. Once you have logged upload it to datazap.me. Also post any mods you have.

I'll pull a log tonight and upload it, thanks

[MatrixE93]

Here's my log on datazap

Does the variance between the HPFP req. and actual indicate HPFP failure? Please let me know what you guys think.

[Ingeniator]

You got some serious high pressure fuelling issues. Either your hp sensor is bad unlikely based on the start and end of the logs or your pump is shot. Did you throw a code during that run if so how long after WOT did the code occur. Your LPFP is dropping pretty low also. This might be the catalyst for the HP injection shutdown. Your also really lean. I'd start by double checking your low side to ensure it isn't causing the injection shutdown if it isn't then you likely need a new hpfp.

[shawntech]

look at your LPFP! hpfp cant keep up if LPFP is 10-20psi low several times

[MatrixE93]

Originally Posted by ls3c6

look at your LPFP! hpfp cant keep up if LPFP is 10-20psi low several times

I see what you mean. So I should be looking at the low pressure pump, low pressure fuel sensor or the fuel filter?

[MatrixE93]

Originally Posted by Ingeniator

Did you throw a code during that run if so how long after WOT did the code occur?

Yes I get codes 29DC and P142E, the engine goes into limp mode only after a couple seconds of WOT.

[Ingeniator]

Originally Posted by ls3c6

look at your LPFP! hpfp cant keep up if LPFP is 10-20psi low several times

That occurs much later though. I agree he needs to check out his lp fuel system. But the pressure looks alright when the initial injector shutdown/hpfp failure happens.

[shawntech]

Originally Posted by MatrixE93

I see what you mean. So I should be looking at the low pressure pump, low pressure fuel sensor or the fuel filter?

from what I've seen/read the LPFP sensor reads high when it fails, I would put a new LPFP in it and see... I'm told these age and perform poorly anyway, that said my car has 93k miles and maintains 5000hpa at all times

[MatrixE93]

One more log, this one is just idle for 18 seconds.


The LPFP stays solid at 72psi while the HPFP fluctuates bewteen 603psi and 785psi.

[Ingeniator]

Hard to say. I still think it is the HPFP. Normally if it is a bad lp sensor the hp rail pressure will stay constant. I'm really leaning toward hpfp. The lpfp fluctuations appear to occur when the pump is pushed hard to supply the injectors for non boost operation.

@Steveaz take a look for him please.

[MatrixE93]

Originally Posted by ls3c6

I did some searching, looks like 29DC is consistant with LPFP, check the HPA should be around 5000 at all times, for reference at warm idle my car runs 50000hpa HPFP/5000hpa LPFP

How steady is the 50000 hpa reading on the HPFP at idle on your car?

Mine slowly rises from 41575 hpa to 54123 hpa over 10 seconds, then drops back down and follows the same rise pattern over ~10 seconds.
http://datazap.me/u/matrixe93/warmed...0&data=1-15-16
Does that look normal?

[shawntech]

Mine is consistent but I will check again at warm idle to confirm

[SteveAZ]

Holy.....I'd say that HPFP has a SERIOUS issue. I have NEVER seen the rail pressures that low with the car running, let alone at WOT . They are basically LPFP pressures and the HPFP is in bypass for the first 3 seconds of that "pull". I'm wondering if that is the HPFP itself failing, or the solenoid in the HPFP failing. Either way, I'd SERIOUSLY consider getting that HPFP replaced and be extremely surprised if that doesn't fix your issue.

Here's an screenshot of what I'm talking about...see how the HPFP pressures are basically identical to the LPFP pressures?



You do not have an LPFP issue and I HIGHLY doubt a lpfp sensor issue. The HPFP is supposed to fail in to bypass mode to allow you to get home in the event of a failure. That is why our injectors are as big as they are and not an issue. You are supposed to be able to make it home on LPFP pressures alone.

PS...If you get it changed and I can get my hands on that HPFP, I'll pay shipping

[shawntech]

Yes my hpfp stays near 50k hpa idling

[MatrixE93]

The verdict is in: Failed HPFP

@ls3c6, @Ingeniator and @SteveAZ THANK YOU for solving this one. My service adviser was a total dick. I went in there with charts printed out and all the details and asked him to only look at the HPFP this time, he said he couldn't use my diagnostic information because it wasn't "theirs". I explained to him that their previous diagnostic said my fuel injectors were causing the issue and I wasn't interested in having them diagnose again. He finally agreed to test ONLY the HPFP. Great, we are finally getting somewhere. I then mentioned that the only reason I was even at their shop was because it is covered under the extended warranty. He plays dumb for several minutes, searching his computer while claiming he has NEVER HEARD OF THE HPFP extended warranty. Asking me questions like "who told you that?", "Did you buy the vehicle used?" Then he turns his screen around and shows me that the only warranty extension for my car is the 8yr turbo warranty. WTF!!!!
So I do a quick google search on my phone and find the SIB# (13 03 09) for him, and "magically" now it is showing up on his computer.

I picked up the car later that day and decided to open the hood just for the hell of it. Found this:




There is no excuse, the tabs aren't even broken off. I know it's not critical, but it is definitely enough for me to never take my car back to that dealer. I am thinking about writing BMW corporate about my experience and asking them to also refund the first $120 diagnostic fee when they told me the injectors were at fault.

[Dmacc]

Originally Posted by MatrixE93

The verdict is in: Failed HPFP

@ls3c6, @Ingeniator and @SteveAZ THANK YOU for solving this one. My service adviser was a total dick. I went in there with charts printed out and all the details and asked him to only look at the HPFP this time, he said he couldn't use my diagnostic information because it wasn't "theirs". I explained to him that their previous diagnostic said my fuel injectors were causing the issue and I wasn't interested in having them diagnose again. He finally agreed to test ONLY the HPFP. Great, we are finally getting somewhere. I then mentioned that the only reason I was even at their shop was because it is covered under the extended warranty. He plays dumb for several minutes, searching his computer while claiming he has NEVER HEARD OF THE HPFP extended warranty. Asking me questions like "who told you that?", "Did you buy the vehicle used?" Then he turns his screen around and shows me that the only warranty extension for my car is the 8yr turbo warranty. WTF!!!!
So I do a quick google search on my phone and find the SIB# (13 03 09) for him, and "magically" now it is showing up on his computer.

I picked up the car later that day and decided to open the hood just for the hell of it. Found this:




There is no excuse, the tabs aren't even broken off. I know it's not critical, but it is definitely enough for me to never take my car back to that dealer. I am thinking about writing BMW corporate about my experience and asking them to also refund the first $120 diagnostic fee when they told me the injectors were at fault.

Glad you solved the issue! Now never go back to that place again!

[shawntech]

glad you got it fixed, my water pump's dead now and never got resolution on jerky engine on cold start :/