This could be an airleak after the airflow meter, any let breathe dragged in here isn t seen by the ECU and so not compensated for and can lean the engine out and can as a consequence permit the engine to rev up taking into account not desired causing gruff running. As its a mechanical irregularity it tends not to slope upon the malfunction buoyant and you can sometimes listen a hissing noise bearing in mind the engine running.
Its moreover worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a not at your best pump will all result in insufficient fuel subconscious delivered to the engine. Might plus be worth cleaning out the idle promptness control motor / valve as these get clogged taking place when carbon and some brake cleaner washed through helps forgive things off.
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 stirring and is warmed up? oftentimes in engine affect many factors may cause the same symptom(s)