This could be an airleak after the airflow meter, any air dragged in here isn t seen by the ECU and appropriately not compensated for and can thin the engine out and can along with permit the engine to rev happening in imitation of not desired causing uncompromising running. As its a mechanical oddity it tends not to viewpoint upon the aberration buoyant and you can sometimes hear a hissing noise like 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 little more about the pain history. It currently has a master tech credited idle air govern valve and tps installed. without upsetting anything, the last (used) ecu and my original, would control in the car without this symptom.
I don't have any check engine lights unless I unplug the MAF sensor. with the MAF is plugged in subsequently the car will stall unless I put my foot upon the accelerator. There is after that an intermittent popping hermetic coming at idle.