Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After irritating 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. yet had issues. incite to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common misery once 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 all sorts of diagnostics on every amalgamated parts (tps, maf, iac). 0-200 every time I bow to it reach the dealer for diagnostics.. on going problems are really accumulation up. I m hesitant to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its moreover worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a not at your best pump will every repercussion in insufficient fuel being delivered to the engine. Might plus be worth cleaning out the idle eagerness manage motor / valve as these acquire clogged occurring taking into consideration carbon and some brake cleaner washed through helps clear things off.
considering I start the car, the engine surges up with 1200 and 2000 rpm back and forth. I changed the IAC and the TPS subsequent to no regulate 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 quickness screw to lower the rpm and it would retain for a while. Now, the engine is every time surging to the reduction where I cannot steer it for frighten of broken to the drive train. Any experienced solution?