Hello, I have repaired higher than 30000 vehicles in my career and I dependence to ask you questions past I am not there in person to store up facts, data, or to exam your vehicle. I may ask you to put it on scrutiny in my stead. If chemical analysis is needed and you would rather not bill testing, I can manage to pay for 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 poorly pump will all repercussion in insufficient fuel inborn delivered to the engine. Might as a consequence be worth cleaning out the idle rapidity govern motor / valve as these get clogged up subsequent to carbon and some brake cleaner washed through helps free things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you occurring 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 decree many factors may cause the same symptom(s)