This could be an airleak after the airflow meter, any let breathe dragged in here isn t seen by the ECU and for that reason not compensated for and can thin the engine out and can then permit the engine to rev happening taking into consideration not desired causing sharp running. As its a mechanical irregularity it tends not to point on the malformation lighthearted and you can sometimes listen a hissing noise taking into consideration the engine running.
Might along with be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a quick irregularity find if you unplug the meter and direct the engine without it. if the engine condition is the similar next chances are the meter or the relationship to it is faulty. Its plus worth cleaning the MAF sensor wires, as they can acquire coated in imitation of dirt more than period which subsequently offsets the reading. Use some log on cleaner or brake cleaner to spray can onto the wires to separate the dirt on no account be next to the wires later everything as they are extremely fragile
This could be a large vacuum leak ,with the MAF connected it is lonely measuring the ventilate that is getting behind the MAF, hence if the intake manifold is sucking in air the expose 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. bearing in mind carb cleaner spray spray can in the area of the hissing next the engine organization and gone you listen the engine stall or rev highly developed there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.