Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to steer off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 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. incite to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common misfortune 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 connected parts (tps, maf, iac). 0-200 every epoch I recognize it reach the dealer for diagnostics.. upon going problems are really extra up. I m undecided to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts in the works and runs at 1750 and within a minute or consequently climbs higher than 2500.. It is dealing out mild though, just artifice vanguard than it should be. I afterward checked the throttle screw plate/return screw, intentionally turned it out and nothing changed. put it support to exactly where it was. No vacuum leak sounds and all friends verified. I vibes good very nearly them as I've been in there a bunch of times..
similar to I start the car, the engine surges in the works amongst 1200 and 2000 rpm put up to and forth. I misused the IAC and the TPS once no tweak in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to adjust the idle rapidity screw to degrade the rpm and it would keep for a while. Now, the engine is all the time surging to the reduction where I cannot steer it for bell of broken to the drive train. Any experienced solution?