Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super announce car that I am ready to drive off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 2-3 alternative 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. back to the dealer.. this period he says, it needs a ECU. I did a lot of research upon them, and found that its a common pain later 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 craving to be re-adjusted? The master tech did every sorts of diagnostics upon every similar parts (tps, maf, iac). 0-200 every period I undertake it accomplish the dealer for diagnostics.. upon going problems are in reality supplement up. I m in two minds to be next 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 tiny more nearly the misery history. It currently has a master tech endorsed idle ventilate direct valve and tps installed. without distressing anything, the last (used) ecu and my original, would rule in the car without this symptom.
like I begin the car, the engine surges happening amid 1200 and 2000 rpm back and forth. I tainted the IAC and the TPS next no fine-tune in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to familiarize the idle readiness screw to demean the rpm and it would retain for a while. Now, the engine is every time surging to the point where I cannot drive it for warning of damage to the steer train. Any experienced solution?