Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to drive off a cliff. had a idle surge burden that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 interchange 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. put up to 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 problem similar to this car.. bought a used one.. more trouble. had the original 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 aligned parts (tps, maf, iac). 0-200 every times I assume it get the dealer for diagnostics.. on going problems are in fact count up. I m unsure to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a little more more or less the hardship history. It currently has a master tech ascribed idle let breathe rule valve and tps installed. without disturbing anything, the last (used) ecu and my original, would govern in the car without this symptom.
as soon as I begin the car, the engine surges up amid 1200 and 2000 rpm support and forth. I tainted the IAC and the TPS in the same way as no fiddle with in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to become accustomed the idle readiness screw to lower the rpm and it would retain for a while. Now, the engine is for eternity surging to the narrowing where I cannot drive it for distress of broken to the drive train. Any experienced solution?