N54 335i jerks on acceleration.

[Showstopper]

Hi Guys

i've read queit a few threads on the same and tried everything that was mentioned to try.

i have a N54 335i E90 which jerks from 4th gear upwards on low rev with some acceleration.

mods: JB4, DP's and BMS intakes

i had BMW have a look at the car a few times and they cannot pick up anything wrong, they had replaced coil packs and they said that they checked injectors and everything else.

i have even tried falling back to the older firmware on JB.

pleeeeeeezzzz!!!!!! someone help and point me to the right direction so that i can have her sorted out.

 

[akash]

Have you tried running the car without the JB?

 

[Woodies]

Sounds like injectors, plugs or coils related. Maybe a carbon build up? Can you run a log and see what is happening when this occurs.
I would take it in for a carbon clean. Check out Carbon Doctor. BMW deny that there is a problem with the carbon build up on direct injection engines.
Good luck, lets us know when you come right.

 

[hoosain]

sounds like a LPFP problem

 

[Showstopper]

injectors and plugs were checked.
coils replaced.

another question:
has anyone used injector cleaner?
im thinking of giving that a shot

 

[boost3d]

do you use NF in your car? or any other addtives/Octane boosters...

sounds like fouled plugs to me...

 

[M3_devil]

Fouled plugs aswell.

 

[DuckKnuckle]

My E90 is doing the same thing (N52) and my mechanic found that my DISA 1 flap has broken off which is causing the misfires at low RPM.

Not sure if it could be the same issue with yours perhaps? DISA 2 is for higher RPM so I have no sort of issues then.

 

[Showstopper]

tried injector cleaner.
i must admit that my consumption went down but it didnt solve my problem after 1 tank.

will try and replace the plugs.
i used NF and use OB1 twice a month now.

if not plugs will try disa.


thanks for some direction guys.

 

[Xack]

Not HPFP. .don't know nothing, just trying to help

 

[Crash_Nemesis]

This might help, I had the same issue with my supercharged e46 M3 on higher gears low RPM. Car was overfueling. A simple retune sorted that out.

Maybe check your logs and see what is going on there in regards to fueling? Maybe fuel pump?

 

[M3_devil]

Stand under correction but N54 does not have DISA flaps.

Does the car still jerk when running stock?

Does the car jerk at higher RPM's as well?

Is they any noticeable difference when the car jerks in terms of which gear you in vs RPM?

Thanks

 

[KevinZa]

Hi
Have you tried cleaning your vanos solenoid's and swopping them around?
Looks like this sorted out a few issues with N54s regarding jerking under acceleration.
They may have to be replaced if it doesn't help. Try getting a diagnostic done to confirm this.

 

[Sleeper135i]

Log it. Replicate the jerk while logging. that's the first step.

 

[freakazoid]

I have the same issue on my 335i. Had the vanos solenoids swopped and then replaced last year. Hope its not that again.

Mine happens at medium acceleration i.e. in between driving like miss daisy and driving like I stole it. Cruising at low to moderate speeds is fine and driving like a maniac is fine.

It happens mostly at half to three quarter throttle. Car will accelerate, misfire, then accelerate again. And this is in 1st, 2nd and 3rd.

Car is on 80 000km and never been for a carbon clean. Guess that should be my first port of call, then plugs.

I also need to have the car checked for a boost leak. Randomly my brakes will be rock hard when the car has stood for a while. If I pop one of the brake vacuum pipes then their is no pressure in the system.

 

[335stepitup]

Agree with the logging as first port of call, but by someone who can interpret the logs correctly and take a correct path to finding the root cause...you haven't mentioned if any faults codes were stored either, is that they are not present or have been deleted without informing you what they were - the stealerships often delete faults and drive again to see if they come up again instead of properly pursuing all possible test plans/causes and actually testing components properly. That said coil packs, fouled/worn spark plugs, carbon build up and occasionally injectors are prime suspects for this kind of issue on the N54. Although usually the injectors are early gen injectors that trouble and will throw mixture adaption faults. So would LPFP or HPFP and would manifest itself under hard acceleration low speed situations also. Could be fuel filter, exhaust blockage, mechanically faulty turbo etc etc also.....N54 has single stage intake without DISA so you won't find a DISA to diagnose. After all is said and done though it needs to be looked at by a reliable professional rather than us taking pot shots at it with piece meal info (no fault of yours but to diagnose properly one should have 1st hand info to work with) and possibly costing you more money than you should spent to fix the issue by throwing parts at the problem based on our calculated guesses.


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[Twinz]

Run a few decent data logs and post it here then one can try to ascertain from there if there is any event staring at us.

 

[Anarchy05]

I need to say I did try injector cleaner when I had injector trouble,but dont use it as indicated a bottle to a full tank,I used a bottle on quarter up to half tank now and then. And it seemed to work as it mostly didnt misfire when starting when I used the cleaner. Also felt like the octane was boosted or sumfin...


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[Chavoos]

Does it have the same symptoms on all maps?
Do you have a Backend flash ?
Btw, leaky injectors usually cause a misfire on cold startup.


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[Showstopper]

no misfire on start up.
problem exist on all maps, even map 0 on JB.
i've checked the plugs and coils - there seems to be a misfire on the coils due to plugs, i will be getting some plugs over the weekend only - will replace plugs and see what happens.

will keep you guys posted.