Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to steer off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After grating 2-3 alternative 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. back to the dealer.. this period he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden similar to 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 all similar parts (tps, maf, iac). 0-200 all period I receive it reach the dealer for diagnostics.. upon going problems are really calculation up. I m in two minds to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might next be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can complete a fast irregularity find if you unplug the meter and govern the engine without it. if the engine condition is the thesame next chances are the meter or the relationship to it is faulty. Its next worth cleaning the MAF sensor wires, as they can acquire coated gone dirt beyond period which later offsets the reading. Use some approach cleaner or brake cleaner to vaporizer onto the wires to sever the dirt on no account be adjacent to the wires taking into consideration anything as they are utterly fragile
This could be a large vacuum leak ,with the MAF similar it is unaccompanied measuring the freshen that is getting similar to the MAF, correspondingly if the intake manifold is sucking in let breathe the ventilate to fuel ratio will be unquestionably out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in imitation of carb cleaner spray can spray can in the area of the hissing afterward the engine direction and taking into consideration you hear the engine stall or rev later there is the leak ,could be a bad vacuum hose bad gasket on the manifold.