This could be an airleak after the airflow meter, any let breathe dragged in here isn t seen by the ECU and correspondingly not compensated for and can thin the engine out and can plus permit the engine to rev going on gone not desired causing rude running. As its a mechanical defect it tends not to slant upon the irregularity light 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 approximately the problem history. It currently has a master tech certified idle ventilate govern valve and tps installed. without touching anything, the last (used) ecu and my original, would run in the car without this symptom.
I don't have any check engine lights unless I unplug the MAF sensor. similar to the MAF is plugged in later the car will stall unless I put my foot on the accelerator. There is afterward an intermittent popping hermetic coming at idle.