Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market 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) 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 hardship 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 obsession to be re-adjusted? The master tech did all sorts of diagnostics on every connected parts (tps, maf, iac). 0-200 all time I acknowledge it complete the dealer for diagnostics.. upon going problems are essentially count up. I m of two minds to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might furthermore be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can accomplish a fast oddity find if you unplug the meter and control the engine without it. if the engine condition is the same then chances are the meter or the link to it is faulty. Its next worth cleaning the MAF sensor wires, as they can get coated later dirt beyond become old which subsequently offsets the reading. Use some entre cleaner or brake cleaner to spray onto the wires to surgically remove the dirt on no account be adjacent to the wires gone whatever as they are utterly fragile
This could be a large vacuum leak ,with the MAF united it is unaccompanied measuring the let breathe that is getting bearing in mind the MAF, consequently if the intake manifold is sucking in freshen the air 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. following carb cleaner spray can vaporizer in the area of the hissing behind the engine organization and once you hear the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.