Hello, I have repaired greater than 30000 vehicles in my career and I need to question you questions in the past I am not there in person to pile up facts, data, or to exam your vehicle. I may question you to feint examination in my stead. If chemical analysis is needed and you would rather not piece of legislation testing, I can have enough money my best advice, Fuel pressure?
Its in addition to 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 upshot in insufficient fuel subconscious delivered to the engine. Might then be worth cleaning out the idle promptness rule motor / valve as these acquire clogged stirring past 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 on 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 action many factors may cause the thesame symptom(s)