Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to drive off a cliff. had a idle surge burden that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 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. still had issues. back up to the dealer.. this get older he says, it needs a ECU. I did a lot of research on them, and found that its a common suffering in the same way as this car.. bought a used one.. more trouble. had the original 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 every sorts of diagnostics upon all amalgamated parts (tps, maf, iac). 0-200 every get older I agree to it do the dealer for diagnostics.. upon going problems are essentially extra up. I m hesitant to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a ill pump will every consequences in insufficient fuel physical delivered to the engine. Might furthermore be worth cleaning out the idle promptness rule motor / valve as these get clogged occurring later than carbon and some brake cleaner washed through helps forgive things off.
in imitation of I start the car, the engine surges stirring together with 1200 and 2000 rpm back up and forth. I changed the IAC and the TPS when no change in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to become accustomed the idle rapidity screw to belittle the rpm and it would keep for a while. Now, the engine is every time surging to the lessening where I cannot steer it for siren of damage to the steer train. Any experienced solution?