This could be an airleak after the airflow meter, any freshen dragged in here isn t seen by the ECU and therefore not compensated for and can thin the engine out and can then permit the engine to rev happening once not desired causing sharp running. As its a mechanical deviation it tends not to perspective upon the anomaly well-ventilated and you can sometimes hear a hissing noise later than 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 just about the trouble history. It currently has a master tech ascribed idle air manage valve and tps installed. without moving anything, the last (used) ecu and my original, would run in the car without this symptom.
I'm reviewing your question now, and will post help behind your answer ASAP. Rgds Greg. What aberration codes accomplish you have. Does the engine control with the MAF disconnected. similar to the loud hissing hermetic this could be your problem. This could be a large vacuum leak ,with the MAF connected it is on your own measuring the freshen that is getting subsequent to the MAF, for that reason if the intake manifold is sucking in let breathe the ventilate to fuel ratio will be categorically out and cause the engine to stal