Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super present car that I am ready to drive off a cliff. had a idle surge hardship that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After bothersome 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. assist to the dealer.. this get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden following 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 all sorts of diagnostics on every joined parts (tps, maf, iac). 0-200 all period I take on it accomplish the dealer for diagnostics.. on going problems are really count up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might after that be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can pull off a fast deformity find if you unplug the meter and control the engine without it. if the engine condition is the same after that chances are the meter or the membership to it is faulty. Its as a consequence worth cleaning the MAF sensor wires, as they can acquire coated as soon as dirt beyond times which subsequently offsets the reading. Use some gate cleaner or brake cleaner to spray onto the wires to cut off the dirt upon no account touch the wires considering everything as they are very fragile
This could be a large vacuum leak ,with the MAF aligned it is single-handedly measuring the air that is getting later the MAF, suitably if the intake manifold is sucking in freshen the air to fuel ratio will be entirely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. behind carb cleaner vaporizer spray in the place of the hissing later than the engine management and similar to you listen the engine stall or rev later there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.