Hello, I have repaired over 30000 vehicles in my career and I dependence to question you questions before I am not there in person to pile up facts, data, or to test your vehicle. I may question you to perform examination in my stead. If laboratory analysis is needed and you would rather not perform testing, I can offer 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 below par pump will every outcome in insufficient fuel innate delivered to the engine. Might along with be worth cleaning out the idle speed rule motor / valve as these get clogged up as soon as carbon and some brake cleaner washed through helps pardon things off.
This could be a large vacuum leak ,with the MAF joined it is deserted measuring the air that is getting similar to the MAF, thus if the intake manifold is sucking in air the ventilate to fuel ratio will be very out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. once carb cleaner vaporizer vaporizer in the area of the hissing subsequent to the engine meting out and taking into consideration you hear the engine stall or rev highly developed there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.