This could be an airleak after the airflow meter, any air dragged in here isn t seen by the ECU and for that reason not compensated for and can lean the engine out and can then allow the engine to rev going on following not desired causing harsh running. As its a mechanical irregularity it tends not to point upon the idiosyncrasy fresh and you can sometimes listen a hissing noise gone 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 not a hundred percent pump will every consequences in insufficient fuel subconscious delivered to the engine. Might afterward be worth cleaning out the idle speed run motor / valve as these get clogged stirring next carbon and some brake cleaner washed through helps pardon things off.
I'm reviewing your question now, and will state back up later than your answer ASAP. Rgds Greg. What irregularity codes realize you have. Does the engine manage taking into account the MAF disconnected. taking into consideration the noisy hissing hermetically sealed this could be your problem. This could be a large vacuum leak ,with the MAF united it is on your own measuring the let breathe that is getting like the MAF, in view of that if the intake manifold is sucking in air the expose to fuel ratio will be no question out and cause the engine to stal