Hi tinyfox,

I have had the exact same problem for a while now, I have managed to diminish the symptoms of the irregular rough/bumpy idle though. I am still looking for a fix, but it is much better now.

What I have done so far,

1. New fuel filter
2. New drive belt tensioner and drive belt - this one made a MAJOR different for some reason, but needed replacing anyway.
3. New catalytic converter - huge difference again, it was blocked!
4. Reco'd injectors - no difference, for some reason WORSE fuel consumption?!?!?!?!?!!?!
5. New leads and plugs

So far these few thing's, along with all the other s**t I have replaced in my servicing, have helped. Although the problem is still there, it is not as noticeable, next on the list is the coil pack and then the ECU FIX with the two new capacitors.

If nothing from there, I'm taking it to my mech who is pretty switched on, I cbf with home fault finding anymore, the most I can be bothered doing now is servicing and bolt on/plug and play replacements hahaha.

Good luck, PM if you find the cause of your problem, I'll keep you updated.