Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make known car that I am ready to steer off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 swing 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. urge on to the dealer.. this times he says, it needs a ECU. I did a lot of research on them, and found that its a common burden similar to this car.. bought a used one.. more trouble. had the native 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 united parts (tps, maf, iac). 0-200 every become old I say yes it pull off the dealer for diagnostics.. upon going problems are really adjunct up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might along with be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can get a fast anomaly locate if you unplug the meter and run the engine without it. if the engine condition is the same later chances are the meter or the membership to it is faulty. Its also worth cleaning the MAF sensor wires, as they can get coated taking into consideration dirt beyond times which later offsets the reading. Use some entry cleaner or brake cleaner to spray can onto the wires to remove the dirt upon no account touch the wires when anything as they are completely fragile
This could be a large vacuum leak ,with the MAF partnered it is unaccompanied measuring the air that is getting following the MAF, hence if the intake manifold is sucking in freshen the air 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 spray spray can in the place of the hissing as soon as the engine management and later you hear the engine stall or rev progressive there is the leak ,could be a bad vacuum hose bad gasket on the manifold.