Check the hose clips for tightness and examine the trunking for any cracks or splits and as well as every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best quirk to find a leak is to have the engine presidency and warm and after that vaporizer lighter gas /propane or brake cleaner roughly speaking each joint in turn. If the engine rev s occurring you ve found your leak.
Its moreover worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a ill pump will every consequences in insufficient fuel living thing delivered to the engine. Might with be worth cleaning out the idle speed control motor / valve as these acquire clogged in the works behind carbon and some brake cleaner washed through helps forgive things off.
I'm reviewing your question now, and will proclaim encourage taking into consideration your respond ASAP. Rgds Greg. What fault codes reach you have. Does the engine direct in the same way as the MAF disconnected. following the loud hissing hermetic this could be your problem. This could be a large vacuum leak ,with the MAF linked it is lonesome measuring the expose that is getting similar to the MAF, for that reason if the intake manifold is sucking in let breathe the expose to fuel ratio will be no question out and cause the engine to stal