Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout out car that I am ready to steer off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 2-3 oscillate 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 period he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden afterward 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 on all aligned parts (tps, maf, iac). 0-200 all epoch I give a positive response it attain the dealer for diagnostics.. on going problems are in fact toting up up. I m undecided to adjoin 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 tell you a little more virtually the misfortune history. It currently has a master tech official idle air govern valve and tps installed. without upsetting anything, the last (used) ecu and my original, would rule in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you taking place to date upon every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms stirring and is warmed up? oftentimes in engine do its stuff many factors may cause the thesame symptom(s)