Check the hose clips for tightness and inspect the trunking for any cracks or splits and as well as every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best artifice to find a leak is to have the engine admin and hot and later spray lighter gas /propane or brake cleaner nearly each joint in turn. If the engine rev s happening you ve found your leak.
Might afterward be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a fast irregularity locate if you unplug the meter and govern the engine without it. if the engine condition is the same later chances are the meter or the attachment to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can get coated taking into account dirt on top of become old which later offsets the reading. Use some read cleaner or brake cleaner to vaporizer onto the wires to remove the dirt on no account be next to the wires taking into account whatever as they are certainly fragile
This could be a large vacuum leak ,with the MAF partnered it is deserted measuring the let breathe that is getting past the MAF, consequently if the intake manifold is sucking in air the air to fuel ratio will be totally 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 vaporizer spray can in the place of the hissing with the engine management and similar to you listen the engine stall or rev future there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.