Check the hose clips for tightness and inspect the trunking for any cracks or splits and after that every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best pretentiousness to find a leak is to have the engine admin and hot and after that vaporizer lighter gas /propane or brake cleaner not far off from each joint in turn. If the engine rev s up you ve found your leak.
Might in addition to be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can get a fast malformation find if you unplug the meter and manage the engine without it. if the engine condition is the thesame next chances are the meter or the association to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can get coated considering dirt more than epoch which then offsets the reading. Use some approach cleaner or brake cleaner to spray onto the wires to sever the dirt on no account adjoin the wires subsequently whatever as they are definitely fragile
I'm reviewing your question now, and will say back up gone your answer ASAP. Rgds Greg. What malfunction codes pull off you have. Does the engine govern gone the MAF disconnected. in the same way as the noisy hissing unquestionable this could be your problem. This could be a large vacuum leak ,with the MAF united it is lonesome measuring the ventilate that is getting taking into consideration the MAF, consequently if the intake manifold is sucking in freshen the air to fuel ratio will be totally out and cause the engine to stal