Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout out car that I am ready to steer off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After frustrating 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. urge on to the dealer.. this epoch he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty afterward this car.. bought a used one.. more trouble. had the indigenous 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 on every similar parts (tps, maf, iac). 0-200 every mature I acknowledge it attain the dealer for diagnostics.. on going problems are in reality add-on up. I m unsure to touch 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 expose flow meter and said it was good. in imitation of I unplug it and run the motor, the car runs scratchy and at 850ish. I can single-handedly guess that my other rebuilt ecu has an issue, or the tps needs to be re-adjusted, or somehow my maf has died in the midst of all this. I don't think the tps has that much rule in the substitute of rpm though? I think it abandoned adjusts it on the subject of 1k..
gone I begin the car, the engine surges up amid 1200 and 2000 rpm put up to and forth. I distorted the IAC and the TPS following no regulate in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to get used to the idle speed screw to degrade the rpm and it would support for a while. Now, the engine is continually surging to the dwindling where I cannot drive it for anxiety of broken to the drive train. Any experienced solution?