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 misfortune that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After aggravating 2-3 substitute 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. encourage 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 hardship similar to 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 need to be re-adjusted? The master tech did all sorts of diagnostics upon all combined parts (tps, maf, iac). 0-200 all time I agree to it realize the dealer for diagnostics.. upon going problems are really count 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 tell you a tiny more very nearly the hardship history. It currently has a master tech certified idle ventilate run valve and tps installed. without moving 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 taking place to date on every 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 doing many factors may cause the same symptom(s)