Check the hose clips for tightness and inspect the trunking for any cracks or splits and furthermore all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best quirk to find a leak is to have the engine supervision and hot and later spray can lighter gas /propane or brake cleaner something like each joint in turn. If the engine rev s occurring you ve found your leak.
Might along with be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a fast irregularity find if you unplug the meter and control the engine without it. if the engine condition is the similar then chances are the meter or the membership to it is faulty. Its moreover worth cleaning the MAF sensor wires, as they can get coated in the manner of dirt higher than times which later offsets the reading. Use some approach cleaner or brake cleaner to spray can onto the wires to surgically remove the dirt upon no account lie alongside the wires once whatever as they are agreed fragile
similar to I begin the car, the engine surges taking place amongst 1200 and 2000 rpm assist and forth. I misused the IAC and the TPS considering no alter in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to adjust the idle eagerness screw to belittle the rpm and it would support for a while. Now, the engine is forever surging to the reduction where I cannot drive it for panic of damage to the steer train. Any experienced solution?