Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to steer 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 exasperating 2-3 swap 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. still had issues. back to the dealer.. this period he says, it needs a ECU. I did a lot of research on them, and found that its a common problem in imitation of 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 obsession to be re-adjusted? The master tech did every sorts of diagnostics upon every related parts (tps, maf, iac). 0-200 every period I acknowledge it reach the dealer for diagnostics.. on going problems are really tallying up. I m in two minds to be adjacent to 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 about the difficulty history. It currently has a master tech recognized idle expose govern valve and tps installed. without moving anything, the last (used) ecu and my original, would govern in the car without this symptom.
in imitation of I begin the car, the engine surges stirring in the company of 1200 and 2000 rpm assist and forth. I untouched the IAC and the TPS considering no bend in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to accustom yourself the idle zeal screw to subjugate the rpm and it would retain for a while. Now, the engine is constantly surging to the reduction where I cannot steer it for siren of broken to the drive train. Any experienced solution?