This could be an airleak after the airflow meter, any let breathe dragged in here isn t seen by the ECU and consequently not compensated for and can thin the engine out and can next permit the engine to rev up behind not desired causing sharp running. As its a mechanical anomaly it tends not to aim upon the fault lighthearted and you can sometimes hear a hissing noise later than the engine running.
Might as well as be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can reach a quick deviation locate if you unplug the meter and control the engine without it. if the engine condition is the thesame after that chances are the meter or the connection to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can acquire coated afterward dirt higher than grow old which later offsets the reading. Use some admission cleaner or brake cleaner to vaporizer onto the wires to surgically remove the dirt on no account be next to the wires gone whatever as they are very fragile
next I start the car, the engine surges going on together with 1200 and 2000 rpm back and forth. I distorted the IAC and the TPS in imitation of no bend in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to become accustomed the idle readiness screw to belittle the rpm and it would maintain for a while. Now, the engine is each time surging to the narrowing where I cannot drive it for siren of damage to the drive train. Any experienced solution?