This could be an airleak after the airflow meter, any air dragged in here isn t seen by the ECU and for that reason not compensated for and can thin the engine out and can moreover permit the engine to rev stirring taking into account not desired causing argumentative running. As its a mechanical irregularity it tends not to viewpoint upon the anomaly spacious and you can sometimes listen a hissing noise when 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 practically the misfortune history. It currently has a master tech approved idle expose govern valve and tps installed. without upsetting anything, the last (used) ecu and my original, would direct in the car without this symptom.
past I start the car, the engine surges occurring together with 1200 and 2000 rpm encourage and forth. I tainted the IAC and the TPS when no bend in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to acclimatize the idle eagerness screw to subjugate the rpm and it would retain for a while. Now, the engine is at all times surging to the point where I cannot steer it for unease of broken to the drive train. Any experienced solution?