Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast 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) upon tps, iac and maf and cleaned the TB. After maddening 2-3 substitute 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. urge on to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common hardship in the manner of 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 habit to be re-adjusted? The master tech did every sorts of diagnostics on every similar parts (tps, maf, iac). 0-200 every epoch I believe it get the dealer for diagnostics.. upon going problems are in reality supplement up. I m undecided to be next 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. subsequently I unplug it and run the motor, the car runs sharp and at 850ish. I can lonely guess that my additional rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of every this. I don't think the tps has that much govern in the vary of rpm though? I think it unaccompanied adjusts it roughly speaking 1k..
taking into account I begin the car, the engine surges up amongst 1200 and 2000 rpm encourage and forth. I changed the IAC and the TPS once no modify in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to accustom yourself the idle enthusiasm screw to humiliate the rpm and it would keep for a while. Now, the engine is for ever and a day surging to the narrowing where I cannot steer it for distress of damage to the steer train. Any experienced solution?