Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around 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 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. yet had issues. back up to the dealer.. this grow old he says, it needs a ECU. I did a lot of research upon them, and found that its a common misfortune taking into account this car.. bought a used one.. more trouble. had the native 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 habit to be re-adjusted? The master tech did every sorts of diagnostics upon all associated parts (tps, maf, iac). 0-200 all get older I agree to it get 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 along with 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 all repercussion in insufficient fuel visceral delivered to the engine. Might furthermore be worth cleaning out the idle rapidity run motor / valve as these get clogged happening with carbon and some brake cleaner washed through helps forgive things off.
considering I start the car, the engine surges in the works between 1200 and 2000 rpm put up to and forth. I misused the IAC and the TPS similar to no tweak in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to adjust the idle zeal screw to demean the rpm and it would hold for a while. Now, the engine is continuously surging to the narrowing where I cannot drive it for startle of broken to the drive train. Any experienced solution?