This could be an airleak after the airflow meter, any let breathe dragged in here isn t seen by the ECU and hence not compensated for and can thin the engine out and can furthermore allow the engine to rev up as soon as not desired causing sharp running. As its a mechanical fault it tends not to point upon the malformation spacious and you can sometimes listen a hissing noise afterward the engine running.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a tiny more just about the difficulty history. It currently has a master tech certified idle air control valve and tps installed. without moving anything, the last (used) ecu and my original, would control in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you taking place 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 happening and is warmed up? oftentimes in engine work many factors may cause the same symptom(s)