I have had this slight stumble which is mostly noticable at idle since the beginning. In fact, I have seen or driven four other cars that had the same problem (two of which I own, one from a forum member, one X305), all above 80000 kms on the clock.
I have since carried out quite a bit of work on the car, checked fuel pressur, replaced fuel filter, replaced distributor cap, rotor, spark plugs, ignition coils, cleaned and re-sealed all injectors, fixed any vacuum leaks (there was one split hose), cleaned and adjusted throttles, adjusted TPS, checked temp sensors, and replaced both oxygen sensors.
I did check with a CO-Meter today, and CO at idle was 0,3% after cold start which is a little low, when warmed up, it was less than the unit could measure. I suspect that the engine is running lean. As this appears to be a systematic problem: What could be the cause?
1964 MkII 4.0 project
2016 RRS SDV8 4.4