Jerky/Stuttery acceleration after initial cold start

[RadiuM]

Mine only did it when it was sitting in the carport on a very cold night < 5c. Any other times it was fine.

FYI, get your parts from overseas and just get them to install it to save a bit of coin.

[1_dez]

Originally Posted by 7smurfs

Interesting! Did you get any codes?

Mine seems to be running fine now, without any sputtering and then it randomly pops a Fuel mixture control code

I have a feeling it is a leaky injector which i got quoted $900 to fix just one....... will try some cheaper alternatives such as coils beforehand.

Where did you get your coils from?!

No codes log avail, sorry.

Parts and install at BMW dealership.

[7smurfs]

Just an update FYI to all of you, I updated to the latest Jb4 firmware and reset all the user adjustment settings to default values and now the problems are gone!

For some odd reason through the various of versions of jb4 all my values were way off i.e. meth was turned on when i don't have meth etc

Car pulls much harder now as a bonus too!

[racer_x]

Did you buy that JB4 second hand?

[1_dez]

A day after i wrote my last post, the car had similar issues that were worse than before the "fix". It got to a point where one cold morning i reversed out of the garage and got an engine light, so it was pushed back into the garage. Took it back into BMW - they had the car for a few days.

Anyway, they did a "leak down test"?? Apparently two injectors were "faulty" and not feeding enough petrol into the engine or something.

They replaced all 6 injectors from '09 to '15 models and updated the software - problem has been fixed for a week now

Although they did mention i should monitor any future misfires as there may be carbon build up behind something. Car is on 70k kms

[7smurfs]

Originally Posted by racer_x

Did you buy that JB4 second hand?

Nope was meant to be brand new - although i didn't buy direct from Burger though...

Originally Posted by 1_dez

They replaced all 6 injectors from '09 to '15 models and updated the software - problem has been fixed for a week now

Although they did mention i should monitor any future misfires as there may be carbon build up behind something. Car is on 70k kms

Damn... I'm assuming you're still under warranty? I was scoping out the price on replacing injectors during my isuses it was close to $1k for 1 injector

[7smurfs]

Looks like the issue has returned.

Will take the car to an indy dealer to check out as this issue is starting annoy me!

Possibilities:
- Adaptation related
- Leaky Injectors
- o2 sensor

[totti84]

I've got 6 brand new injectors in the box which I may sell if you end up needing new ones

[7smurfs]

PM sent!

[martymil]

I had this issue, a trip to advan for a carbon clean and a can on liquid moly injector cleaner fixed the issue and never came back.

I use a can every 4th fill now religiously.

[7smurfs]

Originally Posted by martymil

I had this issue, a trip to advan for a carbon clean and a can on liquid moly injector cleaner fixed the issue and never came back.

I use a can every 4th fill now religiously.

Yeah I'm thinking I'm in need of a liquid injector cleaner.

Which moly injector cleaner did you get?
http://www.supercheapauto.com.au/onl...ecommendations

or

http://www.supercheapauto.com.au/onl...ecommendations

[bayerwhat]

I had the same issue staring at about 60k miles. After a couple months of being annoyed, I went ahead and changed the spark plugs, which were due anyway. Plugs were pretty well fouled-looking. Problem was solved immediately. Got 2mpg more, too.

Interesting, I did get the Check Engine Soon about 200 miles after the new plugs. Went away in a day, came back next day, went away in another day, then gone for good (over 1k miles so far).

[martymil]

I use this one and I get it from advan, you can also get it from supercheap

http://www.supercheapauto.com.au/onl...ecommendations

But don't skimp get the walnut shell blast, I had mine done at 68k and it was pretty dirty in there, I also run a catch can so to minimise the oil going into the intakes.

My car was pretty bad in the mornings but after the blast its always silky smooth.

[7smurfs]

An update: Changed my injectors to the latest index 12 today

Here is a pic of my old injectors (index 7)

All the old injectors:




Bank 1 injectors:



Bank 2 injectors:



Too early to tell whether this has solved my issues however....

[eviled]

Originally Posted by BMW86

How many km's on your car and what have you replaced so far?

What's a km? Killer Mods?

[yawn]

@7smurfs did this ever solve your issue? I have same index injectors and notice a slight stumble at idle every now and then. I've changed plugs and coils still happening. I have new injectors ready to go also (index 12). Just wondering whether your change of injectors fixed your issue?

[7smurfs]

Originally Posted by sharkatron

@7smurfs did this ever solve your issue? I have same index injectors and notice a slight stumble at idle every now and then. I've changed plugs and coils still happening. I have new injectors ready to go also (index 12). Just wondering whether your change of injectors fixed your issue?

Hey sharkatron, yep changing the injectors finally fixed my issue.

I kinda went around the whole issue though and spent a whole of money doing other things such as changing coil packs/sparks/walnut blasting etc

In the end it would've been more economical to bite the bullet and buy injectors. Ended up purchasing from rockauto for about $1k

[yawn]

Yeah I got mine from them too. There's alot of talk whether they are fakes or replicas but I don't hear any stories of them going bad yet. I'll be installing mine as soon as decoupling elements arrive.

At our mileage it doesn't hurt to have the coils and plugs changed. I had the blasting done too as I was approaching 100k km. No regrets though!

[7smurfs]

Originally Posted by sharkatron

Yeah I got mine from them too. There's alot of talk whether they are fakes or replicas but I don't hear any stories of them going bad yet. I'll be installing mine as soon as decoupling elements arrive.

At our mileage it doesn't hurt to have the coils and plugs changed. I had the blasting done too as I was approaching 100k km. No regrets though!

Yep I was honestly quite worried about whether they could be fakes or if i were to get the latest index or not, however it ended up being the latest and basically OEM stamped injectors.

Definitely doesn't hurt to have done the maintenance items though! Although my spark plugs were still very good when I changed them

I'm sitting on 60,000km... though tuned on map 5 for about 20,000kms

[yawn]

So I noticed from reading around your idle goes to 800rpm after being driven a little/warned up - same here! When I first start the car from cold, it starts off at 650rpm. But once it starts to get warm it creeps up to 800rpm. And yeah, I just changed the injectors. So for me, I've changed coils, plugs, injectors, walnut blast all within the last 3k km. I dunno what else there is. Have you made any progress yet?

Weird thing now too is that I'm getting 30FF (underboost) code when all I did was replace injectors. It says on the dash reduced engine power, but I'm still hitting boost and still drives like normal - just have to put up with the half-engine light.

[martymil]

sounds like your vacuum solenoids are on the way out
You have to do a vacuum reading on each one

I had this happen to me and we where pulling hair out
For a few weeks until we done this

The vacuum solenoids had 5 or 6 different revisions
from the original ones

Check your vacuum lines as well

[7smurfs]

Originally Posted by sharkatron

So I noticed from reading around your idle goes to 800rpm after being driven a little/warned up - same here! When I first start the car from cold, it starts off at 650rpm. But once it starts to get warm it creeps up to 800rpm. And yeah, I just changed the injectors. So for me, I've changed coils, plugs, injectors, walnut blast all within the last 3k km. I dunno what else there is. Have you made any progress yet?

Weird thing now too is that I'm getting 30FF (underboost) code when all I did was replace injectors. It says on the dash reduced engine power, but I'm still hitting boost and still drives like normal - just have to put up with the half-engine light.

Hey, I've done exactly the same things as you and nothing has changed the 850rpm idle - i did a plethora of research on it and asked a lot of people and it looks to be normal so I've given up on it now.

The car runs fine, so I've stopped worrying about the 850rpm idle