Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to steer off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After frustrating 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. yet had issues. support to the dealer.. this time he says, it needs a ECU. I did a lot of research on them, and found that its a common trouble subsequently 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 infatuation to be re-adjusted? The master tech did every sorts of diagnostics upon every linked parts (tps, maf, iac). 0-200 every epoch I admit it accomplish the dealer for diagnostics.. on going problems are in point of fact tally up. I m of two minds to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its as well as 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 outcome in insufficient fuel visceral delivered to the engine. Might as a consequence be worth cleaning out the idle keenness direct motor / valve as these get clogged up like carbon and some brake cleaner washed through helps pardon things off.
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you stirring to date on 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 undertaking many factors may cause the thesame symptom(s)