Have a lumpy idle on my 02 jdm Sti.

Took it to Simon (JGM) who kindly checked it via obd. At idle a difference between the 2 banks (in regards to avcs timing) was seen, the lhs bank would sit at 0 the rhs wouldn't go lower than 3/4 and sometimes be as high as 5.

When driving the rhs bank would match the lhs (once they both would be over 5) and it was evident that it's not stuck (at least) and was consistent with my findings that the car smooths out when revved or driven, only stumbles as it idles.

I've read a fair amount on the subject and here's what I've done..

Removed both union oil filters
Removed, inspected and cleaned both oil control solenoids
Checked cambelt is fitted correctly

After doing this I fired it up and the problem was still there. I did rev the engine up a bit and it fell back to idle and didn't seem as bad but then it has it's moments like that (I guess depending on what deg of advance it settles to).

Is this difference between the 2 banks alone going to give me a rocky idle? ie is it enough of a difference in timing?

Also, it seems worse when the car is cold and there appears to be a very faint missfire for the first minute of driving which dissapears after this time. Plus it seems to stink of fuel from cold starts too.

I did have a really bad running from cold start at first and I swapped the coolant sensor for a spare (used one) and it made it almost perfect apart from the feint missfire for the 1st minute of driving.

So now I don't know if this old coolant sensor is slightly goosed too or the cold miss is down to the AVCS being worse when cold (ie oil pressure greater when cold and having a greater mechanical effect on the advancing of the cam wheel)

I have also tried 2 other sets of coil packs and the light missfire doesn't change.