Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to drive off a cliff. had a idle surge misery that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 rotate 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. incite to the dealer.. this mature he says, it needs a ECU. I did a lot of research on them, and found that its a common burden behind 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 craving to be re-adjusted? The master tech did every sorts of diagnostics upon every united parts (tps, maf, iac). 0-200 every time I agree to it reach the dealer for diagnostics.. on going problems are essentially tally up. I m hesitant to be adjacent 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 get a fast defect locate if you unplug the meter and rule the engine without it. if the engine condition is the same later chances are the meter or the relationship to it is faulty. Its as well as worth cleaning the MAF sensor wires, as they can get coated taking into account dirt greater than period which after that offsets the reading. Use some door cleaner or brake cleaner to spray onto the wires to sever the dirt upon no account adjoin the wires later than anything as they are no question fragile
This could be a large vacuum leak ,with the MAF united it is solitary measuring the freshen that is getting as soon as the MAF, so if the intake manifold is sucking in expose the air to fuel ratio will be totally out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. gone carb cleaner spray vaporizer in the place of the hissing as soon as the engine organization and once you hear the engine stall or rev difficult there is the leak ,could be a bad vacuum hose bad gasket on the manifold.