Check the hose clips for tightness and examine the trunking for any cracks or splits and then all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best artifice to find a leak is to have the engine supervision and hot and subsequently spray can lighter gas /propane or brake cleaner roughly each joint in turn. If the engine rev s happening you ve found your leak.
Its also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a in poor health pump will every result in insufficient fuel monster delivered to the engine. Might in addition to be worth cleaning out the idle swiftness govern motor / valve as these acquire clogged in the works next carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF partnered it is by yourself measuring the expose that is getting later than the MAF, therefore if the intake manifold is sucking in ventilate the expose to fuel ratio will be extremely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. later than carb cleaner spray can vaporizer in the place of the hissing in the same way as the engine dispensation and once you hear the engine stall or rev later there is the leak ,could be a bad vacuum hose bad gasket on the manifold.