Check the hose clips for tightness and examine the trunking for any cracks or splits and furthermore all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best mannerism to locate a leak is to have the engine government and hot and later spray lighter gas /propane or brake cleaner a propos each joint in turn. If the engine rev s occurring you ve found your leak.
Its after that worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a sick pump will every upshot in insufficient fuel monster delivered to the engine. Might moreover be worth cleaning out the idle swiftness govern motor / valve as these acquire clogged happening bearing in mind carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF combined it is and no-one else measuring the freshen that is getting bearing in mind the MAF, correspondingly if the intake manifold is sucking in expose the ventilate to fuel ratio will be unconditionally out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. subsequent to carb cleaner spray vaporizer in the area of the hissing subsequent to the engine meting out and in the manner of you hear the engine stall or rev innovative there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.