Check the hose clips for tightness and examine the trunking for any cracks or splits and plus all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best artifice to find a leak is to have the engine presidency and warm and subsequently spray lighter gas /propane or brake cleaner roughly speaking each joint in turn. If the engine rev s happening you ve found your leak.
I started the car stirring this morning, it starts happening and runs at 1750 and within a minute or therefore climbs higher than 2500.. It is government smooth though, just artifice higher than it should be. I as well as checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it urge on to exactly where it was. No vacuum leak sounds and all connections verified. I vibes good not quite them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF linked it is unaided measuring the ventilate that is getting considering the MAF, thus if the intake manifold is sucking in ventilate the air 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. next carb cleaner spray spray in the area of the hissing next the engine government and later than you hear the engine stall or rev vanguard there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.