Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout out car that I am ready to drive off a cliff. had a idle surge misery that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 2-3 exchange 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. put up to to the dealer.. this mature he says, it needs a ECU. I did a lot of research upon them, and found that its a common suffering with 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 dependence to be re-adjusted? The master tech did every sorts of diagnostics on all partnered parts (tps, maf, iac). 0-200 all times I agree to it realize the dealer for diagnostics.. upon going problems are truly totaling up. I m unsure 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 upon the freshen flow meter and said it was good. following I unplug it and rule the motor, the car runs rasping and at 850ish. I can abandoned guess that my additional 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 govern in the alternative of rpm though? I think it lonely adjusts it approaching 1k..
like I begin the car, the engine surges occurring between 1200 and 2000 rpm encourage and forth. I untouched the IAC and the TPS later than no alter in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to become accustomed the idle speed screw to humiliate the rpm and it would sustain for a while. Now, the engine is forever surging to the tapering off where I cannot steer it for anxiety of broken to the steer train. Any experienced solution?