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 pretentiousness to find a leak is to have the engine dealing out and hot and after that vaporizer lighter gas /propane or brake cleaner approximately each joint in turn. If the engine rev s taking place you ve found your leak.
Its furthermore 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 all outcome in insufficient fuel creature delivered to the engine. Might as well as be worth cleaning out the idle eagerness direct motor / valve as these get clogged up with carbon and some brake cleaner washed through helps free things off.
This could be a large vacuum leak ,with the MAF aligned it is single-handedly measuring the air that is getting taking into account the MAF, suitably if the intake manifold is sucking in air the ventilate to fuel ratio will be definitely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. considering carb cleaner spray spray in the place of the hissing following the engine giving out and gone you hear the engine stall or rev well along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.