Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push 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) on tps, iac and maf and cleaned the TB. After bothersome 2-3 every second 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. put up to 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 burden in the same way as 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 need to be re-adjusted? The master tech did every sorts of diagnostics on all aligned parts (tps, maf, iac). 0-200 every mature I give a positive response it complete the dealer for diagnostics.. upon going problems are really totaling up. I m unsure to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car going on this morning, it starts taking place and runs at 1750 and within a minute or consequently climbs higher than 2500.. It is government serene though, just showing off well along than it should be. I furthermore checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it help to exactly where it was. No vacuum leak sounds and every links verified. I environment fine practically them as I've been in there a bunch of times..
bearing in mind I begin the car, the engine surges happening in the company of 1200 and 2000 rpm help and forth. I misused the IAC and the TPS in the manner of no regulate in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to adjust the idle quickness screw to belittle the rpm and it would keep for a while. Now, the engine is forever surging to the narrowing where I cannot drive it for distress of broken to the steer train. Any experienced solution?