Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to drive off a cliff. had a idle surge misery that I researched online and did tests (per the manual) on 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. nevertheless had issues. put up to to the dealer.. this become old he says, it needs a ECU. I did a lot of research on them, and found that its a common difficulty like 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 infatuation to be re-adjusted? The master tech did every sorts of diagnostics on all united parts (tps, maf, iac). 0-200 every era I resign yourself to it do the dealer for diagnostics.. upon going problems are really toting up up. I m hesitant to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car stirring this morning, it starts in the works and runs at 1750 and within a minute or hence climbs greater than 2500.. It is admin smooth though, just quirk superior than it should be. I as a consequence checked the throttle screw plate/return screw, intentionally turned it out and nothing changed. put it help to exactly where it was. No vacuum leak sounds and every associates verified. I vibes good just about them as I've been in there a bunch of times..
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you stirring 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 going on and is warmed up? oftentimes in engine pretense many factors may cause the similar symptom(s)