Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best showing off to find a leak is to have the engine admin and warm and subsequently vaporizer lighter gas /propane or brake cleaner just about each joint in turn. If the engine rev s occurring you ve found your leak.
Might as a consequence be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a quick aberration find if you unplug the meter and govern the engine without it. if the engine condition is the similar subsequently chances are the meter or the link to it is faulty. Its next worth cleaning the MAF sensor wires, as they can get coated behind dirt on top of get older which after that offsets the reading. Use some gate cleaner or brake cleaner to vaporizer onto the wires to cut off the dirt on no account be adjacent to the wires next everything as they are no question fragile
This could be a large vacuum leak ,with the MAF joined it is by yourself measuring the ventilate that is getting behind the MAF, in view of that if the intake manifold is sucking in air the freshen to fuel ratio will be entirely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. like carb cleaner spray spray can in the place of the hissing later than the engine supervision and once you listen the engine stall or rev sophisticated there is the leak ,could be a bad vacuum hose bad gasket on the manifold.