This could be an airleak after the airflow meter, any ventilate dragged in here isn t seen by the ECU and as a result not compensated for and can thin the engine out and can as well as permit the engine to rev occurring bearing in mind not desired causing harsh running. As its a mechanical anomaly it tends not to direction on the defect light and you can sometimes listen a hissing noise in imitation of the engine running.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a little more virtually the misery history. It currently has a master tech recognized idle expose govern valve and tps installed. without heartwarming anything, the last (used) ecu and my original, would control in the car without this symptom.
This could be a large vacuum leak ,with the MAF joined it is deserted measuring the let breathe that is getting similar to the MAF, in view of that if the intake manifold is sucking in freshen the freshen to fuel ratio will be utterly out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. gone carb cleaner vaporizer spray can in the area of the hissing later the engine doling out and following you hear the engine stall or rev well along there is the leak ,could be a bad vacuum hose bad gasket on the manifold.