To answer Yangs question, idle is mildly rough, but definitely noticable and varies.
It started straight after fitting new plugs.
So either I have a faulty spark plug, or the 7's make a difference on idle from the factory spec 6's that were in it, or one coil pack has deteorated / been damaged.
The old plugs looked really old, so may have damaged coils.
They look original so are probably 15 years old.
I've read coil packs do lose their effectiveness over time.
I have had all the symptoms below :
Hard starting - hot
Inconsistent fuel consumption- did a run down to the snow- got 380km with a full tank, loaded a bit
Rough idle- pre new plugs, idle was so smooth, I was frequently checking the gauges to see if the engine was running.
Stalling, a while ago.
Car seems louder and engine sounds different- cruising.
On hard accelleration it all seems fine, just idle and cruise.
It is an expensive trial and error but with all the above..
thanks for all the advice.
having said all that the car just made 237 kw