Check the hose clips for tightness and examine the trunking for any cracks or splits and with every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best quirk to find a leak is to have the engine meting out and hot and next vaporizer lighter gas /propane or brake cleaner with reference to each joint in turn. If the engine rev s up 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 reach a quick defect find if you unplug the meter and direct the engine without it. if the engine condition is the thesame after that chances are the meter or the attachment to it is faulty. Its after that worth cleaning the MAF sensor wires, as they can get coated later dirt exceeding mature which subsequently offsets the reading. Use some gain access to cleaner or brake cleaner to spray onto the wires to separate the dirt on no account be adjacent to the wires behind all as they are completely fragile
This could be a large vacuum leak ,with the MAF combined it is solitary measuring the air that is getting in the manner of the MAF, in view of that if the intake manifold is sucking in air the ventilate to fuel ratio will be no question out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. once carb cleaner spray can spray in the place of the hissing afterward the engine running and similar to you hear the engine stall or rev forward-looking there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.