Check the hose clips for tightness and inspect the trunking for any cracks or splits and along with every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best habit to locate a leak is to have the engine government and warm and next spray can lighter gas /propane or brake cleaner approximately each joint in turn. If the engine rev s happening you ve found your leak.
Might afterward be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick irregularity find if you unplug the meter and govern the engine without it. if the engine condition is the similar later chances are the meter or the attachment to it is faulty. Its plus worth cleaning the MAF sensor wires, as they can get coated past dirt beyond period which next offsets the reading. Use some approach cleaner or brake cleaner to spray onto the wires to separate the dirt upon no account touch the wires with anything as they are unquestionably fragile
once I begin the car, the engine surges taking place with 1200 and 2000 rpm assist and forth. I untouched the IAC and the TPS once no tweak in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to get used to the idle rapidity screw to belittle the rpm and it would preserve for a while. Now, the engine is for all time surging to the lessening where I cannot steer it for fear of broken to the steer train. Any experienced solution?