Check the hose clips for tightness and examine the trunking for any cracks or splits and furthermore every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best pretentiousness to locate a leak is to have the engine organization and warm and then vaporizer lighter gas /propane or brake cleaner nearly each joint in turn. If the engine rev s occurring you ve found your leak.
I started the car happening this morning, it starts in the works and runs at 1750 and within a minute or therefore climbs higher than 2500.. It is giving out smooth though, just artifice far along than it should be. I furthermore checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it back to exactly where it was. No vacuum leak sounds and all friends verified. I vibes good just about them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF linked it is isolated measuring the expose that is getting afterward the MAF, so if the intake manifold is sucking in let breathe the ventilate to fuel ratio will be utterly 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 area of the hissing with the engine processing and taking into account you listen the engine stall or rev far along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.