Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make known car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After aggravating 2-3 substitute 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. 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 misery next 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 need to be re-adjusted? The master tech did all sorts of diagnostics upon all partnered parts (tps, maf, iac). 0-200 all time I undertake it attain the dealer for diagnostics.. on going problems are in point of fact add-on up. I m undecided to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might with be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can pull off a fast anomaly find if you unplug the meter and direct the engine without it. if the engine condition is the thesame next chances are the meter or the connection to it is faulty. Its next worth cleaning the MAF sensor wires, as they can get coated subsequent to dirt exceeding mature which after that offsets the reading. Use some right of entry cleaner or brake cleaner to spray can onto the wires to surgically remove the dirt upon no account adjoin the wires following all as they are unconditionally fragile
This could be a large vacuum leak ,with the MAF linked it is only measuring the freshen that is getting as soon as the MAF, so if the intake manifold is sucking in freshen the air 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. subsequent to carb cleaner spray spray can in the area of the hissing later the engine handing out and taking into account you listen the engine stall or rev difficult there is the leak ,could be a bad vacuum hose bad gasket on the manifold.