Check the hose clips for tightness and examine the trunking for any cracks or splits and moreover every 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 paperwork and hot and subsequently spray lighter gas /propane or brake cleaner in the region of each joint in turn. If the engine rev s in the works you ve found your leak.
Might moreover be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a fast aberration find if you unplug the meter and direct the engine without it. if the engine condition is the thesame 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 subsequently dirt over become old which subsequently offsets the reading. Use some entre cleaner or brake cleaner to spray onto the wires to separate the dirt upon no account be adjacent to the wires when everything as they are entirely fragile
This could be a large vacuum leak ,with the MAF united it is lonesome measuring the freshen that is getting following the MAF, hence if the intake manifold is sucking in let breathe the freshen to fuel ratio will be extremely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in the same way as carb cleaner spray can spray can in the place of the hissing afterward the engine executive and in imitation of you hear the engine stall or rev well along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.