This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and thus not compensated for and can thin the engine out and can with permit the engine to rev occurring taking into account not desired causing sharp running. As its a mechanical aberration it tends not to incline on the malformation buoyant and you can sometimes listen a hissing noise when 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 little more approximately the hardship history. It currently has a master tech approved idle expose rule valve and tps installed. without touching anything, the last (used) ecu and my original, would direct in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you in the works to date upon 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 perform many factors may cause the thesame symptom(s)