Hello, I have repaired on top of 30000 vehicles in my career and I compulsion to question you questions before I am not there in person to gather together facts, data, or to test your vehicle. I may question you to function examination in my stead. If assay is needed and you would rather not proceed testing, I can find the money for my best advice, Fuel pressure?
Its with worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a not a hundred percent pump will every outcome in insufficient fuel bodily delivered to the engine. Might next be worth cleaning out the idle readiness control motor / valve as these acquire clogged occurring 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 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 going on and is warmed up? oftentimes in engine doing many factors may cause the same symptom(s)