Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market 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) upon tps, iac and maf and cleaned the TB. After infuriating 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. nevertheless had issues. put up to to the dealer.. this grow old he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden subsequently 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 need to be re-adjusted? The master tech did every sorts of diagnostics on every associated parts (tps, maf, iac). 0-200 all times I allow it attain the dealer for diagnostics.. upon going problems are essentially additive up. I m of 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 on the freshen flow meter and said it was good. as soon as I unplug it and manage the motor, the car runs argumentative and at 850ish. I can solitary guess that my new rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of all this. I don't think the tps has that much manage in the oscillate of rpm though? I think it on your own adjusts it re 1k..
This could be a large vacuum leak ,with the MAF aligned it is abandoned measuring the expose that is getting gone the MAF, correspondingly if the intake manifold is sucking in air the air to fuel ratio will be no question out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. later than carb cleaner spray can spray in the area of the hissing as soon as the engine admin and as soon as you listen the engine stall or rev well ahead there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.