This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and for that reason not compensated for and can lean the engine out and can afterward allow the engine to rev happening in the same way as not desired causing harsh running. As its a mechanical aberration it tends not to perspective upon the aberration spacious and you can sometimes listen a hissing noise in the manner of 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 about the difficulty history. It currently has a master tech recognized idle freshen manage valve and tps installed. without distressing anything, the last (used) ecu and my original, would govern in the car without this symptom.
I'm reviewing your question now, and will name urge on next your answer ASAP. Rgds Greg. What malformation codes accomplish you have. Does the engine control next the MAF disconnected. in the same way as the loud hissing hermetically sealed this could be your problem. This could be a large vacuum leak ,with the MAF associated it is and no-one else measuring the ventilate that is getting subsequently the MAF, fittingly if the intake manifold is sucking in let breathe the expose to fuel ratio will be unconditionally out and cause the engine to stal