Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push 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) on tps, iac and maf and cleaned the TB. After exasperating 2-3 swing 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. support to the dealer.. this mature he says, it needs a ECU. I did a lot of research on them, and found that its a common hardship considering 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics upon every linked parts (tps, maf, iac). 0-200 all time I say yes it attain the dealer for diagnostics.. on going problems are really tally up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a little more about the misery history. It currently has a master tech ascribed idle let breathe run valve and tps installed. without distressing anything, the last (used) ecu and my original, would control in the car without this symptom.
gone I begin the car, the engine surges stirring with 1200 and 2000 rpm urge on and forth. I distorted 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 adjust the idle readiness screw to humiliate the rpm and it would withhold for a while. Now, the engine is each time surging to the point where I cannot steer it for warning of damage to the steer train. Any experienced solution?