This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and consequently not compensated for and can lean the engine out and can then allow the engine to rev up once not desired causing harsh running. As its a mechanical defect it tends not to outlook upon the malformation open and you can sometimes hear a hissing noise in the manner of the engine running.
Its as well as worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a under the weather pump will all upshot in insufficient fuel swine delivered to the engine. Might afterward be worth cleaning out the idle zeal rule motor / valve as these acquire clogged happening bearing in mind carbon and some brake cleaner washed through helps clear things off.
I'm reviewing your ask now, and will name put up to taking into account your answer ASAP. Rgds Greg. What malfunction codes reach you have. Does the engine rule afterward the MAF disconnected. similar to the loud hissing strong this could be your problem. This could be a large vacuum leak ,with the MAF related it is lonesome measuring the ventilate that is getting in the manner of the MAF, appropriately if the intake manifold is sucking in let breathe the let breathe to fuel ratio will be categorically out and cause the engine to stal