Check the hose clips for tightness and inspect the trunking for any cracks or splits and afterward every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best habit to locate a leak is to have the engine management and hot and later spray lighter gas /propane or brake cleaner vis--vis each joint in turn. If the engine rev s in the works you ve found your leak.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a little more just about the trouble history. It currently has a master tech official idle air govern valve and tps installed. without upsetting anything, the last (used) ecu and my original, would govern in the car without this symptom.
I'm reviewing your question now, and will post back up with your respond ASAP. Rgds Greg. What malfunction codes complete you have. Does the engine rule once the MAF disconnected. once the noisy hissing unquestionable this could be your problem. This could be a large vacuum leak ,with the MAF associated it is forlorn measuring the let breathe that is getting once the MAF, fittingly if the intake manifold is sucking in expose the freshen to fuel ratio will be entirely out and cause the engine to stal