Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to drive off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After bothersome 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. yet had issues. encourage to the dealer.. this period he says, it needs a ECU. I did a lot of research on them, and found that its a common suffering following 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics upon every united parts (tps, maf, iac). 0-200 all epoch I allow it get the dealer for diagnostics.. upon going problems are in reality tally up. I m in two minds to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car up this morning, it starts in the works and runs at 1750 and within a minute or for that reason climbs higher than 2500.. It is running smooth though, just quirk vanguard than it should be. I then checked the throttle screw plate/return screw, intentionally turned it out and nothing changed. put it encourage to exactly where it was. No vacuum leak sounds and every connections verified. I mood fine virtually 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 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 taking place and is warmed up? oftentimes in engine conduct yourself many factors may cause the similar symptom(s)