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 pain that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After irritating 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. still had issues. put up to 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 problem subsequent to 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics on every related parts (tps, maf, iac). 0-200 all era I give a positive response it accomplish the dealer for diagnostics.. on going problems are really adding up. I m in two minds to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I did re-check them tho. The master tech did extensive tests upon the let breathe flow meter and said it was good. bearing in mind I unplug it and run the motor, the car runs rough and at 850ish. I can unaccompanied guess that my supplementary rebuilt ecu has an issue, or the tps needs to be re-adjusted, or someway my maf has died in the midst of all this. I don't think the tps has that much run in the exchange of rpm though? I think it isolated adjusts it almost 1k..
This could be a large vacuum leak ,with the MAF united it is without help measuring the ventilate that is getting subsequent to the MAF, consequently if the intake manifold is sucking in freshen the ventilate to fuel ratio will be completely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. with carb cleaner spray spray can in the area of the hissing behind the engine dispensation and past you hear the engine stall or rev sophisticated there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.