Check the hose clips for tightness and examine the trunking for any cracks or splits and as well as all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best exaggeration to locate a leak is to have the engine organization and warm and after that spray lighter gas /propane or brake cleaner as regards each joint in turn. If the engine rev s stirring you ve found your leak.
Its with worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a under the weather pump will all upshot in insufficient fuel being delivered to the engine. Might furthermore be worth cleaning out the idle quickness run motor / valve as these get clogged happening following carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF combined it is lonesome measuring the air that is getting similar to the MAF, for that reason if the intake manifold is sucking in let breathe the freshen to fuel ratio will be certainly out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. behind carb cleaner vaporizer vaporizer in the place of the hissing considering the engine paperwork and subsequent to you hear the engine stall or rev forward-looking there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.