Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market car that I am ready to steer off a cliff. had a idle surge burden that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 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. still had issues. urge on 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 hardship later than 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 need to be re-adjusted? The master tech did all sorts of diagnostics on all joined parts (tps, maf, iac). 0-200 all become old I recognize it complete the dealer for diagnostics.. on going problems are in fact adding up up. I m hesitant to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I did re-check them tho. The master tech did extensive tests on the freshen flow meter and said it was good. subsequently I unplug it and direct the motor, the car runs sharp and at 850ish. I can only guess that my extra rebuilt ecu has an issue, or the tps needs to be re-adjusted, or someway my maf has died in the midst of all this. I don't think the tps has that much direct in the stand-in of rpm though? I think it without help adjusts it in this area 1k..
taking into consideration I begin the car, the engine surges up with 1200 and 2000 rpm assist and forth. I distorted the IAC and the TPS in the manner of no tweak in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to acclimatize the idle rapidity screw to degrade the rpm and it would maintain for a while. Now, the engine is forever surging to the tapering off where I cannot steer it for apprehension of damage to the steer train. Any experienced solution?