Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to drive 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 bothersome 2-3 rotate 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 mature he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden 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 habit to be re-adjusted? The master tech did every sorts of diagnostics upon every similar parts (tps, maf, iac). 0-200 every time I admit it get the dealer for diagnostics.. on going problems are really extra up. I m of two minds to lie alongside 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 run the motor, the car runs gruff and at 850ish. I can only guess that my additional rebuilt ecu has an issue, or the tps needs to be re-adjusted, or someway my maf has died in the midst of every this. I don't think the tps has that much govern in the every second of rpm though? I think it on your own adjusts it regarding 1k..
later I begin the car, the engine surges in the works amongst 1200 and 2000 rpm back and forth. I tainted the IAC and the TPS next no tweak in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to acclimatize the idle readiness screw to belittle the rpm and it would sustain for a while. Now, the engine is every time surging to the tapering off where I cannot steer it for distress of damage to the steer train. Any experienced solution?