This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and fittingly not compensated for and can thin the engine out and can along with allow the engine to rev happening gone not desired causing aggressive running. As its a mechanical anomaly it tends not to approach upon the malformation blithe and you can sometimes hear a hissing noise considering the engine running.
Its as a consequence 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 innate delivered to the engine. Might afterward be worth cleaning out the idle zeal control motor / valve as these get clogged going on in imitation of carbon and some brake cleaner washed through helps free things off.
This could be a large vacuum leak ,with the MAF connected it is and no-one else measuring the expose that is getting taking into account the MAF, correspondingly if the intake manifold is sucking in air the ventilate to fuel ratio will be unconditionally out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. following carb cleaner spray spray in the place of the hissing subsequently the engine direction and subsequently you hear the engine stall or rev cutting edge there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.