Help with 335i n54 please

[boxter]

Hello,

After my wonderful experience with my last question with my m3, I ask for help with my 335i bi turbo n54.

I´m having hesitation sometimes during hard or soft acceleration between 1000-3500 rpm. At first my bmw dealer changed spark plugs (6) and coils (6) the car improved but the hiccups, pulsation (off fuel or ignition very short). Only sometimes. After that I checked plugs (cleaned and check), DME conector and everything was ok. Bmw dealer changed the pressure transformation (wastegate control) and physically checked wastegate and finally updated the modules included DME (I8AOS). The car improved, more powerful at 5500-7000rpm. Low exhaust sound (I had the conversión valve before), smoother....BUT the hiccup came back! Only during more or less 1/4 fuel tank. Always if I drive a full tank, I have 3/4 tank with perfect work. I feel different performance during a full tank, sometimes more response.

I want to ask advice, I have various hypotesis:

1/ Low fuel pump failure

INPA read in EKP module (option out of DME, before to choose N54), in STATUS READ 1: Actual pump speed=3590 U/min at idle; Target pump speed=7500 U/min
There was a failure memory but storaged in Historic memory: CED4 External error: CAN-ID 0XAA (torque_3) missing
Error counter: 3
Logistic counter 40

2000 km ago
Voltage KL30 14.50 v
target discharge 255 l/h
Engine speed 0
Speed 0
31 ºC
motor voltaje EKP 14v
motor current EKP 10.30
engine speed EKP 6250 1/min
Implausible signal or value
Test condition fulfilled
Error not present now, but already stored
Error would not cause a warning lamp to light up


INPA in STATUS DME/Adaptation mixture read:
Additive adapt. factor bank 1:0
" " bank 2:0

Multiplication adaptation factor b1: 7.045%
" " " b2: 6.293%

I think that value higher 8% would be (air leaks not mesured o low fuel flow)
Do you think that this is bad??


Before today to see this value I suspected always in the low fuel pump...
Yesterday I clean and disconected the EKP module (low fuel pump)

2/Failure Low fuel sensor?

3/ fuel pressure Regulator(inside fuel pump)
4/ Carbon in intake admisión (I have to check) . I think that sometimes DME adjust hight igition advance and the DME cut ignitionto avoid Knock)

THANKS A LOT

[White94RX]

My educated guess is time for an intake port carbon blasting

[boxter]

Thanks a lot,

there are not any error in memory. With DIS nothing in memory but With INPA the great difference between current and target pump speed.

Ok I will check intake

[ben4bama]

Mine hiccuped when cold was low pressure fuel pump sensor, not the pump.
When hesitating on accelerating on highway it needed an injector once and carbon blasting another

[boxter]

Thank you
I have hesitating under soft and hard accelararion sometimes only.And with high gear (4,5 OR 6th) and more with full throttle.

- - - Updated - - -

Today I have checked with DIS and the multiplicative adaptation are 6.5 more or less similar with INPA.Nevertherless additive adapt. Are zero.
Do you think those data are high?
what are the maximum value? I know for M3 S50b32 (info in DIS), -10 to +8% is ok.

- - - Updated - - -


Mine hiccuped when cold was low pressure fuel pump sensor, not the pump.
When hesitating on accelerating on highway it needed an injector once and carbon blasting another
Do you have any error memory?

[ben4bama]

I had faults for fuel pump and injectors but not for carbon buildup. I don't know what the faults were

[diazr1843]

how many miles?

[boxter]

Hi!
More important data for the problem that I forgot to tell you.
When the hesitation problem started (20000km and 1 year ago),also my dealer changed the cover gasket and cover (broken), because there was oil leaks and there were coils with oils.
1200 km ago I checked the oil leak and... I found oil in a coil (3rd). I cleaned with conector cleaning (spray) the coil and all injector conectors and another ones (pressure sensor and all conectors that my dealer could touched.

Also I swiched off the EKP module (fuel pressure control)
For the moment I have not had hesitation (2 full fuel tank).

Can coil with oil produce hesitation?

Thanks a lot

Note: my multiplicative adaptation (fuel mix) are 6-7 %. I remember it lower long time ago.

[ben4bama]

You need to get the spark plug gasket replaced regardless. I would think oil could interfere with the coil operation.

[boxter]

how many miles?
I am sorry
155000km

[diazr1843]

Have the intake ever been walnut blasted?

[boxter]

I have not cleaned it never

[diazr1843]

I have not cleaned it never
then you really need to do it. I did my at 46000 miles and can't not believe how bad it was and my car was like new again. is a must do for the n54.

[boxter]

Hello guys.
My car continues with failure.I found too a bad electric wires instalation for a gps conection that was in OBDII.The wires were touching and naked...The car seems to work better.But sometimes I have again a little hiccup.
Today I have checked with dis the car.No error in memory.Only 12 kg/h air mass flow at 85 'Centrigrade cooling temp. I remembered 14 or 15 two years ago. And less multiplicative adaptation.Now 7 and before more or less zero.
Could I have an air leak?
do you think that a carbon build in intake could produce low mass air flow too?
could you check with inpa o dis these value? Air mass flow and multiplicative adaptation please?
I want to clean intake but I would like to know what have I to check about air leaks.
thanks a lot

Pd It is importan check at service temperature..more or less 85 centrigrades degrees for compare.

[mniemiec]

Silly, but have you checked your intake air filter? When my dual cone intakes were "slightly" dirty I would get these hiccups during spirited acceleration. Replaced dual cone filters and was all better. Just throwing out there.

[boxter]

Silly?.?!
Please have your medication
For the polite rest of forum:I have not dual cones.My air filter always is clean.

[jcianci12]

Also I swiched off the EKP module (fuel pressure control)
For the moment I have not had hesitation (2 full fuel tank).


What do you mean you switch off the ekp module? Did you swap it out?