Check the hose clips for tightness and examine the trunking for any cracks or splits and along with every 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 paperwork and hot and subsequently spray can lighter gas /propane or brake cleaner on the subject of each joint in turn. If the engine rev s going on you ve found your leak.
Its next 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 result in insufficient fuel inborn delivered to the engine. Might plus be worth cleaning out the idle swiftness govern motor / valve as these get clogged in the works gone carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF partnered it is abandoned measuring the freshen that is getting like the MAF, fittingly if the intake manifold is sucking in ventilate the freshen 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. later than carb cleaner vaporizer spray in the place of the hissing subsequent to the engine running and taking into account you hear the engine stall or rev later there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.