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 hardship that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 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. nevertheless had issues. help to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common misery with 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 craving to be re-adjusted? The master tech did all sorts of diagnostics upon all amalgamated parts (tps, maf, iac). 0-200 all grow old I say you will it accomplish the dealer for diagnostics.. upon going problems are really extra up. I m unsure to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car happening this morning, it starts happening and runs at 1750 and within a minute or so climbs higher than 2500.. It is admin serene though, just pretension difficult than it should be. I next checked the throttle screw plate/return screw, on purpose turned it out and nothing changed. put it assist to exactly where it was. No vacuum leak sounds and every connections verified. I vibes good just about them as I've been in there a bunch of times..
taking into account I begin the car, the engine surges happening with 1200 and 2000 rpm incite and forth. I misrepresented the IAC and the TPS afterward no correct in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to get used to the idle keenness screw to belittle the rpm and it would withhold for a while. Now, the engine is at all times surging to the lessening where I cannot steer it for bell of broken to the steer train. Any experienced solution?