Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops 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 a pain 2-3 alternating 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. still had issues. back to the dealer.. this times he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble once 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics on all joined parts (tps, maf, iac). 0-200 all period I undertake it do the dealer for diagnostics.. on going problems are in fact calculation up. I m unsure to touch 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 attain a quick aberration locate if you unplug the meter and control the engine without it. if the engine condition is the similar subsequently chances are the meter or the association to it is faulty. Its furthermore worth cleaning the MAF sensor wires, as they can get coated similar to dirt higher than era which later offsets the reading. Use some log on cleaner or brake cleaner to spray onto the wires to sever the dirt upon no account lie alongside the wires subsequently all as they are entirely fragile
This could be a large vacuum leak ,with the MAF similar it is unaided measuring the air that is getting subsequent to the MAF, thus if the intake manifold is sucking in freshen the expose to fuel ratio will be utterly out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. when carb cleaner spray can vaporizer in the area of the hissing later than the engine dispensation and next you hear the engine stall or rev forward-looking there is the leak ,could be a bad vacuum hose bad gasket on the manifold.