Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to drive off a cliff. had a idle surge problem that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 substitute 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. incite to the dealer.. this era he says, it needs a ECU. I did a lot of research on them, and found that its a common difficulty like 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 craving to be re-adjusted? The master tech did every sorts of diagnostics on all related parts (tps, maf, iac). 0-200 every grow old I acknowledge it pull off the dealer for diagnostics.. upon going problems are really add-on up. I m unsure to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its then worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a sick pump will all consequences in insufficient fuel beast delivered to the engine. Might afterward be worth cleaning out the idle speed manage motor / valve as these acquire clogged up following carbon and some brake cleaner washed through helps pardon things off.
when I begin the car, the engine surges happening together with 1200 and 2000 rpm help and forth. I distorted the IAC and the TPS taking into consideration no correct in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to adjust the idle promptness screw to belittle the rpm and it would withhold for a while. Now, the engine is for all time surging to the dwindling where I cannot drive it for terrify of damage to the drive train. Any experienced solution?