This could be an airleak after the airflow meter, any ventilate dragged in here isn t seen by the ECU and hence not compensated for and can lean the engine out and can with allow the engine to rev up subsequent to not desired causing sharp running. As its a mechanical idiosyncrasy it tends not to face on the idiosyncrasy fresh and you can sometimes hear a hissing noise similar to 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 little more roughly the difficulty history. It currently has a master tech qualified idle freshen run valve and tps installed. without heartwarming anything, the last (used) ecu and my original, would rule in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you up to date upon all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms occurring and is warmed up? oftentimes in engine ham it up many factors may cause the similar symptom(s)