Check the hose clips for tightness and examine the trunking for any cracks or splits and moreover every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best artifice to locate a leak is to have the engine processing and warm and next spray can lighter gas /propane or brake cleaner on the order of each joint in turn. If the engine rev s occurring you ve found your leak.
Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can realize a quick oddity find if you unplug the meter and control the engine without it. if the engine condition is the same then chances are the meter or the relationship to it is faulty. Its after that worth cleaning the MAF sensor wires, as they can acquire coated past dirt exceeding era which after that offsets the reading. Use some entry cleaner or brake cleaner to vaporizer onto the wires to surgically remove the dirt upon no account be adjacent to the wires bearing in mind everything as they are very fragile
subsequent to I begin the car, the engine surges taking place along with 1200 and 2000 rpm back and forth. I misused the IAC and the TPS with no change in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to become accustomed the idle readiness screw to lower the rpm and it would maintain for a while. Now, the engine is forever surging to the tapering off where I cannot drive it for apprehension of damage to the drive train. Any experienced solution?