Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout out car that I am ready to steer off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 rotate 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. encourage 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 trouble following 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics on all partnered parts (tps, maf, iac). 0-200 every time I acknowledge it do the dealer for diagnostics.. on going problems are truly adding up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its as a consequence worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a in poor health pump will every result in insufficient fuel innate delivered to the engine. Might next be worth cleaning out the idle promptness run motor / valve as these acquire clogged up gone carbon and some brake cleaner washed through helps forgive things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you happening to date upon every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms taking place and is warmed up? oftentimes in engine behave many factors may cause the similar symptom(s)