Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff 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 a pain 2-3 substitute 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 time he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble behind 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics upon all amalgamated parts (tps, maf, iac). 0-200 all epoch I agree to it complete the dealer for diagnostics.. upon going problems are truly totaling up. I m in two minds to be next 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 air flow meter and said it was good. bearing in mind I unplug it and control the motor, the car runs argumentative and at 850ish. I can isolated guess that my additional rebuilt ecu has an issue, or the tps needs to be re-adjusted, or somehow my maf has died in the midst of every this. I don't think the tps has that much direct in the rotate of rpm though? I think it forlorn adjusts it in this area 1k..
behind I begin the car, the engine surges happening with 1200 and 2000 rpm back and forth. I tainted the IAC and the TPS in the manner of no bend 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 swiftness screw to humiliate the rpm and it would preserve for a while. Now, the engine is continually surging to the tapering off where I cannot steer it for danger signal of damage to the steer train. Any experienced solution?