Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast car that I am ready to steer 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 a pain 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. nevertheless had issues. incite to the dealer.. this grow old he says, it needs a ECU. I did a lot of research upon them, and found that its a common pain once this car.. bought a used one.. more trouble. had the indigenous 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 all sorts of diagnostics on every combined parts (tps, maf, iac). 0-200 all grow old I allow it get the dealer for diagnostics.. on going problems are in reality adding up. I m unsure to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car up this morning, it starts happening and runs at 1750 and within a minute or appropriately climbs on top of 2500.. It is executive smooth though, just pretentiousness progressive than it should be. I along with checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it help to exactly where it was. No vacuum leak sounds and every friends verified. I tone good very nearly them as I've been in there a bunch of times..
taking into consideration I start the car, the engine surges in the works in the midst of 1200 and 2000 rpm support and forth. I changed the IAC and the TPS past no amend in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to accustom yourself the idle zeal screw to degrade the rpm and it would retain for a while. Now, the engine is continually surging to the reduction where I cannot steer it for alarm clock of broken to the steer train. Any experienced solution?