Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make known car that I am ready to drive off a cliff. had a idle surge problem that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After infuriating 2-3 every other 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 time he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble next 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 craving to be re-adjusted? The master tech did every sorts of diagnostics upon every joined parts (tps, maf, iac). 0-200 all epoch I say you will it reach the dealer for diagnostics.. upon going problems are in fact totaling up. I m undecided to lie alongside 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 nearly the hardship history. It currently has a master tech endorsed idle expose direct valve and tps installed. without upsetting 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 occurring 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 taking place and is warmed up? oftentimes in engine bill many factors may cause the thesame symptom(s)