Check the hose clips for tightness and examine the trunking for any cracks or splits and furthermore every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best habit to find a leak is to have the engine supervision and hot and then vaporizer lighter gas /propane or brake cleaner in the region of each joint in turn. If the engine rev s going on you ve found your leak.
Might moreover be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a fast idiosyncrasy locate if you unplug the meter and rule the engine without it. if the engine condition is the thesame then chances are the meter or the attachment to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can acquire coated following dirt exceeding period which subsequently offsets the reading. Use some door cleaner or brake cleaner to spray can onto the wires to cut off the dirt on no account adjoin the wires taking into consideration whatever as they are totally fragile
subsequent to I start the car, the engine surges happening in the company of 1200 and 2000 rpm urge on and forth. I distorted the IAC and the TPS behind no amend in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to familiarize the idle quickness screw to belittle the rpm and it would maintain for a while. Now, the engine is at all times surging to the dwindling where I cannot steer it for fear of broken to the steer train. Any experienced solution?