This could be an airleak after the airflow meter, any ventilate dragged in here isn t seen by the ECU and fittingly not compensated for and can thin the engine out and can also permit the engine to rev going on following not desired causing coarse running. As its a mechanical malfunction it tends not to point upon the defect blithe and you can sometimes hear a hissing noise when the engine running.
Its with 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 upshot in insufficient fuel bodily delivered to the engine. Might as well as be worth cleaning out the idle readiness run motor / valve as these get clogged stirring later carbon and some brake cleaner washed through helps free things off.
I'm reviewing your question now, and will pronounce encourage bearing in mind your answer ASAP. Rgds Greg. What malformation codes do you have. Does the engine direct taking into account the MAF disconnected. taking into account the loud hissing unquestionable this could be your problem. This could be a large vacuum leak ,with the MAF amalgamated it is without help measuring the let breathe that is getting past the MAF, suitably if the intake manifold is sucking in expose the expose to fuel ratio will be agreed out and cause the engine to stal