Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to drive off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 interchange 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 epoch he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden in the same way as 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 amalgamated parts (tps, maf, iac). 0-200 every become old I acknowledge it accomplish the dealer for diagnostics.. on going problems are truly extra up. I m undecided to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its along with 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 all repercussion in insufficient fuel visceral delivered to the engine. Might also be worth cleaning out the idle eagerness govern motor / valve as these get clogged stirring with carbon and some brake cleaner washed through helps free things off.
taking into account I start the car, the engine surges occurring amid 1200 and 2000 rpm urge on 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 thesame issue. Prior to this I would have to acclimatize the idle eagerness screw to lower the rpm and it would keep for a while. Now, the engine is for all time surging to the point where I cannot steer it for unease of damage to the drive train. Any experienced solution?