Check the hose clips for tightness and examine the trunking for any cracks or splits and plus all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best exaggeration to find a leak is to have the engine executive and warm and next vaporizer lighter gas /propane or brake cleaner a propos each joint in turn. If the engine rev s up you ve found your leak.
Might as well as be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a fast fault find if you unplug the meter and run the engine without it. if the engine condition is the similar then chances are the meter or the connection to it is faulty. Its in addition to worth cleaning the MAF sensor wires, as they can acquire coated next dirt higher than mature which then offsets the reading. Use some log on cleaner or brake cleaner to vaporizer onto the wires to cut off the dirt upon no account be adjacent to the wires later all as they are agreed fragile
This could be a large vacuum leak ,with the MAF combined it is by yourself measuring the ventilate that is getting when the MAF, correspondingly if the intake manifold is sucking in ventilate the air to fuel ratio will be agreed out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. when carb cleaner vaporizer spray can in the area of the hissing behind the engine paperwork and bearing in mind you listen the engine stall or rev far along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.