This could be an airleak after the airflow meter, any expose dragged in here isn t seen by the ECU and so not compensated for and can thin the engine out and can in addition to permit the engine to rev up with not desired causing brusque running. As its a mechanical anomaly it tends not to point on the malfunction fresh and you can sometimes hear a hissing noise when the engine running.
Might plus be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it. if the engine condition is the same later chances are the meter or the association to it is faulty. Its furthermore worth cleaning the MAF sensor wires, as they can acquire coated later than dirt on top of get older which after that offsets the reading. Use some door cleaner or brake cleaner to vaporizer onto the wires to sever the dirt upon no account be next to the wires subsequently anything as they are totally fragile
like I start the car, the engine surges stirring along with 1200 and 2000 rpm back up and forth. I changed the IAC and the TPS behind no amend in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to accustom yourself the idle promptness screw to degrade the rpm and it would hold for a while. Now, the engine is permanently surging to the dwindling where I cannot drive it for distress signal of broken to the steer train. Any experienced solution?