long story short, 99 FI BB with 30k km (one owner only before me), worked quite good for a thousand km, i've made an Oil/Filters/Plugs change during the line, and also CCT.
After 600km form service started to stutter and can't hold idle, initially it was also difficult to start when cold, probably for the wet plugs.
Battery 12,7-12,8v cold, 13,8-14v idle and 14,3v over 2k (and also 14,4 at 5k).
All sparks (600km use) badly fouled, and after some test found fuel dripping from the air port of fuel pressure regulator.
Changed plugs with old good one and new OEM FPR from cms, same problem.
It goes quite good when cold, after warm up it start to run bad, for my understanding one cylinder stop from firing, from the smell for me is too much fuel, but could be something else.
Checked ECT (1,6kohm at 30°C), strange thing is when warm couldn't measure any readings....will try better tomorrow
Injectors impedance 14,8kohm all around, tested for spark between every coil and a bolt on the engine and every cylinder show spark, not sure if this is enough to say coils and wires are good.
No error in the diagnostic memory. Fuel pump prime ok, measured fuel from return line (after new FPR) as per service manual , its around 300ml in ten seconds (manual say 220cm3 al least).
A bit lost right now, any help appreciated