Jerky/Stuttery acceleration after initial cold start

[yawn]

Originally Posted by 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

I won't go too off topic with the current thread, I'll start a new one. But thanks martymil.

Originally Posted by 7smurfs

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

Yeah, was just also think about whether genuine from the dealer spark plugs would help too. There has been debate upon debate as to whether there is any difference between them and the bosch ones... Apparently they are not gapped the same? Sure you could gap yourself but are there any other differences? Reading around there seems to be alot of controversy as to whether they are really the same or not.

[7smurfs]

Originally Posted by sharkatron

Yeah, was just also think about whether genuine from the dealer spark plugs would help too. There has been debate upon debate as to whether there is any difference between them and the bosch ones... Apparently they are not gapped the same? Sure you could gap yourself but are there any other differences? Reading around there seems to be alot of controversy as to whether they are really the same or not.

I had bosch ones that had only done like 2,000kms and I did the change to genuine BMW plugs to see if it did anything... absolutely nothing and was a waste of money lol

I read through the same thing regarding the controversy between OEM/bosch etc

[yawn]

7smurfs

Heya, I thought maybe I'd update my findings with regards to an elevated rpm at idle when warm.

Unlike you, I also had rough idling soon after changing spark plugs. I thought it could have been installation error, but after doing some research, looks like it is a fairly common problem. However, others have suggested resetting adaptation values - in particular throttle adaptation. I decided to give this a shot, and what do you know - rough idling is gone. rpm is also down. Thought you might want to give this a try if the high rpm is frustrating you.

Ah yeah, nearly forgot - you'll need to clear codes after resetting throttle adaptation - rpm will keep bouncing when you turn on the engine until codes have been cleared.

[Kirst]

The 850rpm idle is normal. Every n54 does it. @7smurfs

[7smurfs]

Originally Posted by Kirst

The 850rpm idle is normal. Every n54 does it. @7smurfs

Yep! Thanks Kirst, I did quite a bit of questioning/research and came to that conclusion also