Check the hose clips for tightness and inspect 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 way to locate a leak is to have the engine paperwork and warm and subsequently vaporizer lighter gas /propane or brake cleaner not far off from each joint in turn. If the engine rev s stirring 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 quick malfunction locate if you unplug the meter and rule the engine without it. if the engine condition is the similar then chances are the meter or the relationship to it is faulty. Its afterward worth cleaning the MAF sensor wires, as they can get coated later dirt higher than era which next offsets the reading. Use some entre cleaner or brake cleaner to spray can onto the wires to remove the dirt upon no account adjoin the wires once all as they are agreed fragile
This could be a large vacuum leak ,with the MAF linked it is and no-one else measuring the freshen that is getting once the MAF, in view of that if the intake manifold is sucking in let breathe the freshen to fuel ratio will be completely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. subsequently carb cleaner vaporizer vaporizer in the place of the hissing subsequently the engine dealing out and subsequent to you hear the engine stall or rev highly developed there is the leak ,could be a bad vacuum hose bad gasket on the manifold.