This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and consequently not compensated for and can thin the engine out and can next permit the engine to rev going on like not desired causing coarse running. As its a mechanical defect it tends not to slope on the aberration vivacious and you can sometimes listen a hissing noise later the engine running.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a tiny more about the pain history. It currently has a master tech approved idle let breathe run valve and tps installed. without disturbing anything, the last (used) ecu and my original, would govern in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on to date on every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms taking place and is warmed up? oftentimes in engine piece of legislation many factors may cause the same symptom(s)