This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and thus not compensated for and can lean the engine out and can in addition to permit the engine to rev stirring similar to not desired causing gruff running. As its a mechanical deviation it tends not to incline on the idiosyncrasy lively and you can sometimes hear a hissing noise as soon as 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 very nearly the suffering history. It currently has a master tech endorsed idle expose manage valve and tps installed. without upsetting anything, the last (used) ecu and my original, would rule in the car without this symptom.
I don't have any check engine lights unless I unplug the MAF sensor. like the MAF is plugged in then the car will stall unless I put my foot upon the accelerator. There is also an intermittent popping unquestionable coming at idle.