This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and hence not compensated for and can lean the engine out and can next permit the engine to rev taking place once not desired causing scratchy running. As its a mechanical fault it tends not to viewpoint on the deformity fresh and you can sometimes hear a hissing noise subsequent to the engine running.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a tiny more nearly the difficulty history. It currently has a master tech endorsed idle ventilate rule valve and tps installed. without heartwarming anything, the last (used) ecu and my original, would run in the car without this symptom.
This could be a large vacuum leak ,with the MAF related it is lonely measuring the freshen that is getting subsequent to the MAF, consequently if the intake manifold is sucking in ventilate the expose to fuel ratio will be entirely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. taking into consideration carb cleaner spray can spray can in the area of the hissing as soon as the engine giving out and with you listen the engine stall or rev vanguard there is the leak ,could be a bad vacuum hose bad gasket on the manifold.