Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops car that I am ready to steer off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 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. assist 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 suffering when this car.. bought a used one.. more trouble. had the indigenous 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 upon all aligned parts (tps, maf, iac). 0-200 all time I understand it reach the dealer for diagnostics.. on going problems are in reality additive up. I m unsure 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 ventilate flow meter and said it was good. like I unplug it and manage the motor, the car runs rasping and at 850ish. I can forlorn guess that my supplementary 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 interchange of rpm though? I think it by yourself adjusts it a propos 1k..
later than I start the car, the engine surges going on amid 1200 and 2000 rpm back and forth. I tainted the IAC and the TPS subsequent to no change in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to familiarize the idle swiftness screw to lower the rpm and it would preserve for a while. Now, the engine is constantly surging to the tapering off where I cannot steer it for distress of damage to the drive train. Any experienced solution?