Check the hose clips for tightness and examine the trunking for any cracks or splits and with all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best mannerism to locate a leak is to have the engine government and warm and then spray lighter gas /propane or brake cleaner just about each joint in turn. If the engine rev s stirring 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 do a fast anomaly locate if you unplug the meter and run the engine without it. if the engine condition is the similar later chances are the meter or the link to it is faulty. Its also worth cleaning the MAF sensor wires, as they can acquire coated later dirt beyond era which subsequently offsets the reading. Use some entry cleaner or brake cleaner to vaporizer onto the wires to sever the dirt upon no account adjoin the wires later all as they are definitely fragile
taking into consideration I begin the car, the engine surges stirring together with 1200 and 2000 rpm put up to and forth. I tainted the IAC and the TPS afterward no modify in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to familiarize the idle swiftness screw to belittle the rpm and it would retain for a while. Now, the engine is every time surging to the reduction where I cannot drive it for distress signal of damage to the drive train. Any experienced solution?