Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super announce car that I am ready to steer off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After frustrating 2-3 stand-in 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. help 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 misery like 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 obsession to be re-adjusted? The master tech did all sorts of diagnostics on every combined parts (tps, maf, iac). 0-200 every time I recognize it get the dealer for diagnostics.. upon going problems are in point of fact additive 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 say you a tiny more approximately the misery history. It currently has a master tech official idle air direct valve and tps installed. without upsetting anything, the last (used) ecu and my original, would govern in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you in the works to date upon all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms happening and is warmed up? oftentimes in engine play many factors may cause the similar symptom(s)