Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast car that I am ready to drive off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After bothersome 2-3 interchange used IAC s, I took it to the master tech at lexus. He said it was the IAC valve. He tried my used ones.. and finally a rebuilt one. nevertheless had issues. help to the dealer.. this grow old he says, it needs a ECU. I did a lot of research on them, and found that its a common difficulty like this car.. bought a used one.. more trouble. had the indigenous one rebuilt by a specialist.. and that s where I am at now.. Put it in tonight and the car idles at 2k rpm. Does the TPS compulsion to be re-adjusted? The master tech did every sorts of diagnostics on every joined parts (tps, maf, iac). 0-200 all become old I admit it complete the dealer for diagnostics.. upon going problems are really adding up. I m in two minds to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick oddity locate if you unplug the meter and manage the engine without it. if the engine condition is the similar subsequently chances are the meter or the association to it is faulty. Its moreover worth cleaning the MAF sensor wires, as they can get coated behind dirt over time which then offsets the reading. Use some entry cleaner or brake cleaner to vaporizer onto the wires to sever the dirt upon no account be adjacent to the wires taking into account everything as they are utterly fragile
This could be a large vacuum leak ,with the MAF partnered it is forlorn measuring the let breathe that is getting in imitation of the MAF, appropriately if the intake manifold is sucking in expose the let breathe to fuel ratio will be very out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in the manner of carb cleaner vaporizer spray can in the place of the hissing as soon as the engine management and in imitation of you hear the engine stall or rev complex there is the leak ,could be a bad vacuum hose bad gasket on the manifold.