engine trouble

[M7]

anyone had any trouble with their engine on their 9n?

this is the 2nd time i have had bother, 1st time it was the coil pack and it needed replacing. the engine was running well under powered and it was very jumpy and juddery.

again i am having the same problem, although i have not lost any power this time, it just idle's up and down and between 2k and 3k rev's the engine judders when i am driving, regardless of what gear i am in.

anyone experienced this before? or know why it happens?

thanks.