[335i E92]

Hi All

Finally after 12 months of investigating my rough idle has been fixed.

After having my plugs changed last year my car instantly developed an idle misfire. The car would idle at 600rpm and after a few idle shakes and shivers would then rise to 750rpm.

I stopped in at Darren Woods yesterday to run a test on my lpfp and hpfp (which were fine and well within spec) these were the final two parts on my check list to try to remedy the rough idle.

Whilst plugged in Mike reset the LVS Values, this is a reset that is to be run after changing plugs or coils. (Adaptation of stratification)

Immediately the car started to idle a lot smoother, apparently it can take 500 – 1000 miles to fully adjust but its night and day already and much smoother on idle and acceleration.

The LVS reset is a new test module that appeared on their GT1 diagnostic kit last week. Woods to the rescue once more!!

Hope this helps anyone out there with same issue.

[idnan]

Great news!

I had a very slight shake on idle before I changed my plugs but since doing them its got noticebly worse to the point where I hate sitting in traffic.

I must get that done when I'm down there

[335i E92]

Can't believe it’s taken me a year to solve, its bin a right pita. As you said it's annoying when you’re sat at the lights and the whole car is shaking with each misfire.

Definitely get this done as its made a massive difference not just to the idle but it feels silky smooth on acceleration too.

[m1bjr]

What is LVS short for?

You can reset these parameters with both the JB4 and the BT scantool

[idnan]

Originally Posted by m1bjr

What is LVS short for?

You can reset these parameters with both the JB4 and the BT scantool

I'll have to check that when I get home today as I have both of them. I haven't reset any parameters since the plug change.

[m1bjr]

"Reset Adaptations" IIRC.
Terry did suggest to not do it with the JB4 as it might be a bit 'lumpy' until it relearns.
Personally I found it only takes a full warm up and a quick drive.

I think its Long and short term fuel trims etc. that get a reset too.

[335i E92]

Not sure what LVS means, googled it but can't find anything. I'll check with Mike.

If you're trying to reset via BT then check this tread out.

http://www.e90post.com/forums/showthread.php?t=386376

[idnan]

Did you ever reset the adaptations mentioned in Mr 5's thread or was that the first time you did any adaptation reset?

[335i E92]

Originally Posted by idnan

Did you ever reset the adaptations mentioned in Mr 5's thread or was that the first time you did any adaptation reset?

I don't have a BT cable, Darren Woods had previously re-set the general adaptations but this didn't work. As i said this new test module only came through to them recently.

[Quisp]

That is great news! Where can this be done, a dealer or independant?
Thanks!!!

[RichJ]

I have had similar symptoms for the last year since the injectors and spark plugs were replaced. Will have to ask my dealer. Does it take a while to reset?

[335i E92]

Just go in to your dealer and speak to the service manager, explain the symptoms and quote the stated test module. Ask for the head tech to look at the new adaptation reset that's meat to be used post plugs or coils being replaced and BOOM!! Hopefully you'll all put this BS problem to bed!!

Only took 2 mins to reset, good luck...

[RichJ]

Thanks a lot, it's due a serviced soon so i'll make sure it's looked at!! Apart from that it has been fine since!

[Quisp]

took it to the dealer and gave them the info and they had no idea what i was talking about. I mentioned the GT1 diagnostic and he said that was an old version and they were on 3 or something. If anyone in the US gets this done please post your work order or if anyone else has a copy that i couilds show that would be great.

[idnan]

I cured my rough idle by the method mentioned in post 7 using the BT tool.

[335i E92]

Update…

Idnan, great to here the BT fix worked for you!!

I’ve now done 450 miles since I had the LVS adaptation reset, whilst the car is running a lot smoother the rough idle is still present and just as bad, no sign of improvement at all.

It’s looking like the BT cable fix is the ONLY known cure for this pita rough idle. I’ve been talking to some guys on N54TECH and people suffering the same rough idle are also confirming that Mr5’s BT fix has worked for them.

Steve, nice to see you also on n54tech, if your BT cable works on multiple cars it would great to borrow it for a day as you mentioned. Only ting is I live in Manchester so this could be difficult with you being in Somerset.

If anyone else is closer to Manchester and has a BT cable that I can use to run this update it would be a massive help to me. I could by one but not being that tech minded I prob wouldn’t use it again so £300 is a bit of a sting

(Quisp) I would suggest you also try to find someone locally who has BT cable or just buy on eand run the fix yourself.

[idnan]

When I say worked, I still have the slight shake that I had before but no where near as bad as it was when I had the plugs changed.

IMO the BT cable is a must if you're running a modified n54 (except JB4 users) as you need be able to investigate any issues if they come up. It's a shame that I bought a second hand one with only one VIN number left as I'm up Manchester quite often.

[335i E92]

Originally Posted by idnan

When I say worked, I still have the slight shake that I had before but no where near as bad as it was when I had the plugs changed.

IMO the BT cable is a must if you're running a modified n54 (except JB4 users) as you need be able to investigate any issues if they come up. It's a shame that I bought a second hand one with only one VIN number left as I'm up Manchester quite often.

It might take a few days to fully adapt, how many miles have you covered since the reset?

I plan on keeping the car for another coupe of years at least so maybe it will be a good investment to get one anyway as you say.

Did you follow mr5’s to the letter and re-set all the below with engine switched off?

• Air Control Adjustment
• Throttle Valve Adaptation
• Fuel/Air Adaptation
• Secondary Air Injection Adaptation

It’s also important to run the car at between 2 – 2.5k for 5 mins and then leave to idle for 5 mins after the reset. Did you do this?

[idnan]

Originally Posted by 335i E92

It might take a few days to fully adapt, how many miles have you covered since the reset?

I plan on keeping the car for another coupe of years at least so maybe it will be a good investment to get one anyway as you say.

Did you follow mr5’s to the letter and re-set all the below with engine switched off?

• Air Control Adjustment
• Throttle Valve Adaptation
• Fuel/Air Adaptation
• Secondary Air Injection Adaptation

It’s also important to run the car at between 2 – 2.5k for 5 mins and then leave to idle for 5 mins after the reset. Did you do this?

I reset all the adaptations mentioned by Mr 5 but couldn't do the bit where I had to run the car between 2-2.5k for 5 minutes properly due to the roads around mine.

I've done about 100miles around town since the reset and it does feel better. Although I was having a few performance related issues beforehand which have hopefully gone away now.

[335i E92]

Originally Posted by idnan

I reset all the adaptations mentioned by Mr 5 but couldn't do the bit where I had to run the car between 2-2.5k for 5 minutes properly due to the roads around mine.

I've done about 100miles around town since the reset and it does feel better. Although I was having a few performance related issues beforehand which have hopefully gone away now.

Is your idle rising from 600 to 750 when it stumbles or was yours not doing that previously?

This is what I’m hoping to rectify with the BT cable.

[Quisp]

I do have a BT cable but was hoping to maybe get it dopne by the dealership just in case.
I will try Mr5s fix this weekend.
What do you think it will do with the Dinan flash?

[335i E92]

Originally Posted by Quisp

I do have a BT cable but was hoping to maybe get it dopne by the dealership just in case.
I will try Mr5s fix this weekend.
What do you think it will do with the Dinan flash?

Perform the resets with the engine off and you should be fine. I have an Evolve flash and will be doing exactly the same as soon as i get a BT cable.

Good luck, let me know how you get on next week amigo!!