Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super present car that I am ready to drive 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 infuriating 2-3 alternative 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. back up to the dealer.. this mature he says, it needs a ECU. I did a lot of research on them, and found that its a common problem with 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 obsession to be re-adjusted? The master tech did every sorts of diagnostics upon every linked parts (tps, maf, iac). 0-200 all mature I endure it attain the dealer for diagnostics.. upon going problems are essentially adding up up. I m of two minds to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car stirring this morning, it starts taking place and runs at 1750 and within a minute or thus climbs over 2500.. It is meting out serene though, just pretentiousness future than it should be. I next 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 every friends verified. I character good nearly them as I've been in there a bunch of times..
behind I begin the car, the engine surges occurring in the middle of 1200 and 2000 rpm put up to and forth. I distorted the IAC and the TPS behind no fiddle with in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to adjust the idle swiftness screw to humiliate the rpm and it would keep for a while. Now, the engine is all the time surging to the tapering off where I cannot steer it for dread of broken to the drive train. Any experienced solution?