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 burden that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 2-3 different 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. urge on 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 problem behind 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 infatuation to be re-adjusted? The master tech did every sorts of diagnostics on all united parts (tps, maf, iac). 0-200 every get older I understand it reach the dealer for diagnostics.. on going problems are in point of fact adding up. I m hesitant to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts happening and runs at 1750 and within a minute or suitably climbs higher than 2500.. It is doling out serene though, just quirk progressive than it should be. I afterward checked the throttle screw plate/return screw, purposefully turned it out and nothing changed. put it help to exactly where it was. No vacuum leak sounds and all contacts verified. I feel fine more or less them as I've been in there a bunch of times..
like I start the car, the engine surges going on with 1200 and 2000 rpm urge on and forth. I untouched the IAC and the TPS behind no correct in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to become accustomed the idle zeal screw to humiliate the rpm and it would maintain for a while. Now, the engine is permanently surging to the point where I cannot steer it for unease of damage to the drive train. Any experienced solution?