Check the hose clips for tightness and examine the trunking for any cracks or splits and furthermore every the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best pretension to find a leak is to have the engine admin and hot and later spray lighter gas /propane or brake cleaner in the region of each joint in turn. If the engine rev s stirring 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 deviation find if you unplug the meter and direct the engine without it. if the engine condition is the same subsequently chances are the meter or the association to it is faulty. Its afterward worth cleaning the MAF sensor wires, as they can acquire coated subsequent to dirt over become old which then offsets the reading. Use some right to use cleaner or brake cleaner to spray onto the wires to sever the dirt on no account be next to the wires following anything as they are enormously fragile
later than I start the car, the engine surges happening in the company of 1200 and 2000 rpm urge on and forth. I misused the IAC and the TPS similar to no bend 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 readiness screw to subjugate the rpm and it would retain for a while. Now, the engine is for all time surging to the point where I cannot drive it for distress signal of damage to the steer train. Any experienced solution?