Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout out car that I am ready to steer off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After irritating 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. nevertheless had issues. support to the dealer.. this period he says, it needs a ECU. I did a lot of research on them, and found that its a common misery behind 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 every sorts of diagnostics upon all connected parts (tps, maf, iac). 0-200 all time I allow it get the dealer for diagnostics.. on going problems are truly adjunct up. I m in two minds to adjoin 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. subsequent to I unplug it and control the motor, the car runs sharp and at 850ish. I can without help guess that my other rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of all this. I don't think the tps has that much rule in the stand-in of rpm though? I think it unaccompanied adjusts it on 1k..
afterward I start the car, the engine surges up amongst 1200 and 2000 rpm back up and forth. I distorted the IAC and the TPS later 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 swiftness screw to demean the rpm and it would keep for a while. Now, the engine is for eternity surging to the lessening where I cannot drive it for radio alarm of broken to the steer train. Any experienced solution?