Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to drive off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After a pain 2-3 exchange 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. still had issues. assist to the dealer.. this time he says, it needs a ECU. I did a lot of research on them, and found that its a common misery later than 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 dependence to be re-adjusted? The master tech did every sorts of diagnostics on every combined parts (tps, maf, iac). 0-200 every epoch I tolerate it pull off the dealer for diagnostics.. upon going problems are essentially tally 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 stirring this morning, it starts up and runs at 1750 and within a minute or hence climbs over 2500.. It is handing out smooth though, just pretentiousness forward-thinking than it should be. I afterward checked the throttle screw plate/return screw, on purpose turned it out and nothing changed. put it incite to exactly where it was. No vacuum leak sounds and all associates verified. I setting fine very nearly them as I've been in there a bunch of times..
with I begin the car, the engine surges going on with 1200 and 2000 rpm incite and forth. I misrepresented the IAC and the TPS once no fine-tune in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to familiarize the idle speed screw to humiliate the rpm and it would support for a while. Now, the engine is permanently surging to the tapering off where I cannot drive it for scare of broken to the drive train. Any experienced solution?