M54B25 stalling issues

[NOmoreBLING]

Hey all,

I've been lurking on this forum for some time now and now I decided to post as my car needs some immediate attention. I hope to get some tips on how to deal with this problem. I have no mechanical background, but I know how to do some basic repairs, this however, is my first BMW car and it seems more complicated than my previous VW Golf IV GTI.
Quick history - M54B25 touring, I bought this car 9 months ago, apart from new oil and filters, it required only new CCV lines. And that's it - 9 months of happiness :)
The problem happened a few days ago. I've started the engine and for a few seconds it was idling a bit roughly, when I pressed the gas pedal it died immediately.
Symptoms:
-starts on, but rpm is a bit lower than should be, idle is a bit rough
-pressing gas causes engine to stall, but pressing gas with max force causes engine to rev up
-when I put the gearbox in "drive" and release break pedal, the car moves forward, pressing gas however makes the engine die

So far far, I checked:
-fuel pump - fuses are ok, makes noise when I turn the ignition on
-today I've removed the airbox and checked the throttle plate - it opens when gas pedal is pressed.
- INPA shows some errors and they are as follows:

E R R O R M E M O R Y R E P O R T
-------------------------------------
Date: 09/08/18 20:52:35
ECU: MS430DS0
JobStatus: OKAY
Variant: MS430DS0
-------------------------------------------------------------
RESULT: 9 errors in error memory !
-------------------------------------------------------------
190 Lambda probe heating downstrem sensor 1
Error frequency : 1
Logistic counter: 40
N_32 704.00 rpm
MAF 98.05 mg/stk
VLS_DOWN_1 0.43 V
R_MV_LS_DIAG_DOWN_1 65535.00 Ohm
aufgetreten vor (rel. BZ) 141.40 h
---
---
---
Cat-sensor heater defective
Error to relevant
Error debounce
Error currently available
stat. Error
Errorcode: BE 78 01 28 16 12 56 FF E7 4C
-------------------------------------------------------------
227 lambda contol tolerance Bank 1
Error frequency : 9
Logistic counter: 39
N_32 704.00 rpm
MAF 92.60 mg/stk
TCO 96.00 Grad C
LAM_MV_1 25.00 %
aufgetreten vor (rel. BZ) 8.00 h
Deviation rich
---
---
FUS active to Failure entry
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: E3 B9 09 27 16 11 C0 C0 EC 82
-------------------------------------------------------------
202 Lambda regulating limit Bank1
Error frequency : 4
Logistic counter: 40
N_32 704.00 rpm
TCO 63.75 Grad C
R_LS_UP_1 203.00 Ohm
VLS_UP_1 0.06 V
aufgetreten vor (rel. BZ) 6.10 h
Mixture limit rich
---
---
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: CA B1 04 28 16 95 CB 0C EC 95
-------------------------------------------------------------
228 lambda contol tolerance Bank 2
Error frequency : 1
Logistic counter: 35
N_32 704.00 rpm
MAF 114.39 mg/stk
TCO 96.75 Grad C
LAM_MV_2 21.48 %
aufgetreten vor (rel. BZ) 2.20 h
Deviation rich
---
---
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: E4 B1 01 23 16 15 C1 B7 EC BC
-------------------------------------------------------------
238 burning fail Cylinder 1
Error frequency : 1
Logistic counter: 35
TCO 96.75 Grad C
N_32_TOL 736.00 rpm
MAF_TOL 114.39 mg/stk
MAF_BOL 108.94 mg/stk
aufgetreten vor (rel. BZ) 2.20 h
---
---
Misfire CARB_B4
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: EE B4 01 23 C1 17 15 14 EC BC
-------------------------------------------------------------
240 burning fail Cylinder 3
Error frequency : 1
Logistic counter: 35
TCO 96.75 Grad C
N_32_TOL 736.00 rpm
MAF_TOL 114.39 mg/stk
MAF_BOL 108.94 mg/stk
aufgetreten vor (rel. BZ) 2.20 h
---
---
Misfire CARB_B4
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: F0 B4 01 23 C1 17 15 14 EC BC
-------------------------------------------------------------
203 Lambda regulating limit Bank2
Error frequency : 1
Logistic counter: 35
N_32 704.00 rpm
TCO 96.75 Grad C
R_LS_UP_2 154.00 Ohm
VLS_UP_2 0.07 V
aufgetreten vor (rel. BZ) 2.20 h
Mixture limit rich
---
---
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: CB B1 01 23 16 C1 9A 0D EC BC
-------------------------------------------------------------
239 burning fail Cylinder 2
Error frequency : 2
Logistic counter: 35
TCO 96.75 Grad C
N_32_TOL 768.00 rpm
MAF_TOL 130.73 mg/stk
MAF_BOL 98.05 mg/stk
aufgetreten vor (rel. BZ) 2.10 h
---
---
Misfire CARB_B4
---
Error to relevant
Error debounce
Error currently not available
sporadic Error
Errorcode: EF B4 02 23 C1 18 18 12 EC BD
-------------------------------------------------------------
8 air flow meter
Error frequency : 7
Logistic counter: 40
N_32 544.00 rpm
THR 24.24 Grad TPS
ISAPWM_ISA 68.75 %
VMAF 0.00 V
aufgetreten vor (rel. BZ) 0.00 h
---
KS--> Ground or open circuit
---
---
Error to relevant
Error debounce
Error currently available
sporadic Error
Errorcode: 08 F2 07 28 11 1F B0 00 EC D2
================================================== ===========


Hope to get some tips where to look and what to check to get "the beast" up and running :)

[edjack]

Disconnect the air flow meter and start the engine? Does it now run correctly? The MAF may be bad, or the wiring to the MAF is bad.

You also have a problem with the O2 sensor heating circuit. Fixing this may solve the sensor error codes.

[geargrinder]

Agreed.

The MAF error occured 7 times, logistics counter 40 means it's basically happening all the time, so that's definitely a 'real deal' error....
It says ground or open circuit, that could either mean the MAF is failing internally, or, could be a wiring issue.

Likewise the Lambda control (mixture control) errors have happened many times and almost all of them happened at last startup so they are probably happening all the time. Long shot could be coming from the bad MAF but I'd also check the Bank 1 O2 sensors and/or connectors. The Bank 1 post-cat sensor definitely has a heater error which is a hard-wiring error and should be looked at.

Then you have seen occaisional misfires on 1,2,3 (Bank 1 obv), but they only happened once about 5-starts ago (logistics 35)...
Likewise the Bank 2 mixture error only happened once that same 5-starts-ago...

My guess on those is that they are just 'side-effect' symptoms of the primary things that are wrong - MAF and/or O2 stuff. Vacuum leaks thankfully seem to be out because your errors are rich running not lean.... which also points to perhaps a bad MAF...

My advice would be same as ed's basically:
- Clean up MAF connector (spray connector w contact cleaner & inspection etc. ) you can try spraying MAF cleaner on the inside part of the sensor itself but these are not as prone to contamination problems as the old hot-wire types so that tends not to do much anymore...
- Inspect O2 sensor connectors and wiring condition under the car, particularly Bank 1 post-cat, fix anything you find there and / or re-seat the connectors

Clear codes and try a restart and see what comes back

If the MAF errors come right back, clear again, then try running it without the MAF connected as Ed suggests... That will throw a new 'MAF' error but if the car runs well otherwise and doesn't throw the other errors, you can be pretty sure the MAF is bad and causing the other problems...

[NOmoreBLING]

Thank you for replying. Today in the morning I removed the the MAF and cleaned it. It seems OK, because when I start the engine and disconnect it, engine starts working unevenly.
Once I removed MAF, I went further and removed intake parts down to the throttle body. When I removed the idle control valve to take a closer look, it did not make the "rattle can" noise it should make. At that point I was 90% sure I found the culprit.
So I cleaned the valve with some carb cleaner and piece of cloth, assembled it back together ........and now my engine works just fine :) I did a small test drive after I cleared error codes - 20 km and no errors.
Tomorrow I'll take it for a longer ride and hook up inpa to take a look at short and long term fuel trims, lambda etc.... I hope the ICV was the main reason for stalling, but I want to be extra sure.

[djb2]

Check the intake boots very carefully for cracks.

For those reading this in the future, "lambda control" doesn't mean that the lambda sensors are faulty. It means that the lambda sensors are working, and the ECU can't control the fuel/air mixture. That generally means an intake air leak.

[geargrinder]

Well... I understand your “simplification for simple future readers” Point. A lambda control error doesn’t literally mean the sensor is bad, BUT it can be the case. Drifting aging O2s or bad connections giving bad readings and the DME still unable to hit the desired target can and does occur. And in this case there are ALSO hard O2 errors tho granted they are downstream so shouldn’t be affecting the control loop aside from primary O2 diagnosis.... and the actual control error says “rich” which means in this case not a vac leak.

Dont get me wrong I’m not saying O2s are for sure ops running problem (tho he does have a hard error on a post cat one - that one ain’t fixin itself ) I’m just saying they should be on the list to further check out IF the MAF / ICV don’t fix everything.

[blarf]

An oxygen sensor won't work unless it's hot. I think generally even the unheated ones will stay hot enough once the engine has been running for a while. However running without a heater will delay going into closed loop mode. Check the resistance at the sensor side of the plug across the ground an heater pins (your DME thinks it's got an open circuit so that should be real easy to check). If the resistance is OK at the sensor side, probe the DME connector (either with the sensor plugged in or with the sensor unplugged and the two pins on the other end of the harness jumped). If that checks out okay hit the wiring diagrams and see if there's a fuse in the circuit (then check to see if it's blown or if your fuse box looks like it's corroded).

Lambda control vs lambda regulating limit is, I think, long-term vs short-term (unsure which is which) fuel trims.

That MAF voltage is zero which again means the DME thinks there's an open circuit. Check the DME and MAF side of that wiring. Perhaps your DME connector is getting corroded?

That misfire though... an obvious first step is to look for vacuum leaks, but.... how's the coil pack wiring look? Do the coils share a common ground with the MAF and oxygen sensor heaters?

Edit: Looks like fuses 1, 3, and 4 are in play and all three circuits ground through the DME. So. Go find the DME ground points and see how they look.

[NOmoreBLING]

This week is going to be busy for me so I'll propably look into this on weekend. Unless something goes wrong with the car :)

Wysłane z mojego ALE-L21 przy użyciu Tapatalka

[geargrinder]

That misfire though... an obvious first step is to look for vacuum leaks, but.... how's the coil pack wiring look? Do the coils share a common ground with the MAF and oxygen sensor heaters?

Edit: Looks like fuses 1, 3, and 4 are in play and all three circuits ground through the DME. So. Go find the DME ground points and see how they look.

Yeah... IME when you have other clear symptoms like MAF / O2 hard errors, its worthwhile not wasting time w/ the misfire codes yet... It very well may be that the bad MAF signals are causing bad mixture which is causing it to hit the control limits and causing the misfires... Get the 'hard errors' out of there first, then see what comes back...

But yea the ground checks are a good call.

[blarf]

Yeah... IME when you have other clear symptoms like MAF / O2 hard errors, its worthwhile not wasting time w/ the misfire codes yet... It very well may be that the bad MAF signals are causing bad mixture which is causing it to hit the control limits and causing the misfires... Get the 'hard errors' out of there first, then see what comes back...

But yea the ground checks are a good call.

Yeah, mixture problems like a bad MAF can cause a misfire. I'm a bit suspicious seeing the oxygen sensor resistance at max (65535 = 0xFFFF = open circuit) and the MAF voltage at zero (also likely an open circuit) instead of seeing something wrong but not at either the high or low limit.

[NOmoreBLING]

Yeah, so it's been a few weeks since I solved the problem. I did as geargrinder suggested - checked the things. Up to now I drove over 4 000 kilometres and the check engine popped up 3- 4 times, for 1-2 hours each time. What is interesting is that the check engine would show up only when there was rainy weather. I used to have a similar issue in the past with my previous car - Golf IV. I removed the catalyst and had to use a metal spacer between the lambda sensor and exhaust so that the LPG system could run. After that mod, every time there was rain I had check engine light for a few hours. Later on I found out that they guy who welded in the spacer in my exhaust did a lousy job and there was air leak that would cause problems. I welded it again and problem was solved.