This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and for that reason not compensated for and can thin the engine out and can with permit the engine to rev up considering not desired causing unfriendly running. As its a mechanical defect it tends not to slant on the defect lighthearted and you can sometimes hear a hissing noise similar to the engine running.
Its afterward 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 every consequences in insufficient fuel instinctive delivered to the engine. Might as well as be worth cleaning out the idle promptness run motor / valve as these acquire clogged stirring as soon as carbon and some brake cleaner washed through helps clear things off.
This could be a large vacuum leak ,with the MAF joined it is without help measuring the let breathe that is getting similar to the MAF, suitably if the intake manifold is sucking in air the freshen to fuel ratio will be no question out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. taking into account carb cleaner vaporizer vaporizer in the place of the hissing next the engine executive and bearing in mind you listen the engine stall or rev unconventional there is the leak ,could be a bad vacuum hose bad gasket on the manifold.