Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote 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) upon tps, iac and maf and cleaned the TB. After frustrating 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. still had issues. incite to the dealer.. this get older he says, it needs a ECU. I did a lot of research on them, and found that its a common hardship in the same way as this car.. bought a used one.. more trouble. had the native 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 all sorts of diagnostics upon all combined parts (tps, maf, iac). 0-200 all time I receive it get the dealer for diagnostics.. on going problems are really extra up. I m unsure 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 tiny more about the trouble history. It currently has a master tech qualified idle ventilate manage valve and tps installed. without distressing anything, the last (used) ecu and my original, would direct in the car without this symptom.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you happening to date on all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms going on and is warmed up? oftentimes in engine be active many factors may cause the similar symptom(s)