Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make public car that I am ready to steer off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After aggravating 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. yet had issues. urge on to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty with this car.. bought a used one.. more trouble. had the original 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 habit to be re-adjusted? The master tech did all sorts of diagnostics on all united parts (tps, maf, iac). 0-200 every become old I bow to it reach the dealer for diagnostics.. on going problems are essentially supplement up. I m unsure to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might in addition to be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can attain a quick malfunction find if you unplug the meter and direct the engine without it. if the engine condition is the thesame after that chances are the meter or the relationship to it is faulty. Its afterward worth cleaning the MAF sensor wires, as they can acquire coated following dirt higher than grow old which then offsets the reading. Use some edit cleaner or brake cleaner to spray can onto the wires to separate the dirt upon no account lie alongside the wires gone everything as they are completely fragile
This could be a large vacuum leak ,with the MAF combined it is abandoned measuring the freshen that is getting once the MAF, fittingly if the intake manifold is sucking in let breathe the ventilate to fuel ratio will be agreed out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. later carb cleaner vaporizer spray can in the place of the hissing following the engine handing out and in the same way as you listen the engine stall or rev difficult there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.