R56 cooper s sometimes miss fires between 2000 and 3000 revs

[BrianBon]

Hi
Anybody any advise on this
R56 2007 cooper s sometimes miss fires between 2000 and 3000 revs sometimes.
normally around 2800 revs it happens just like the plugs are not firing. Then it kicks in and away it goes.
when over 3000 revs no problem or at full song.

Changed All spark plugs.
I have changed two of the Ignition coils, thinking of changed the rest.
61000 miles.

Or is it something else ??

I was talking to another Cooper s owner who had the same problem shortly after buying it but his was under warranty so he just brought it back and it was fixed so he does not know what they did.

Thanks for looking

Regards Brian

[irlmin]

Hi Brian
A diagnostic session will find the problem I am sure , coil failure will always manifest itself with a very serious misfire on the particular cylinder , any warning lights like EML light coming on is the problem prominent when cold or hot or always
plugs are always a good starting point . was there any improvement when you fitted the new plugs
G

[BrianBon]

G.
I changed the plugs and have now changed all the coils.
Happened mostly warm, or hot
Running much better.
no warning lights coming on at all before.
Will see how we go.
Thanks