Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market car that I am ready to drive off a cliff. had a idle surge hardship that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After grating 2-3 stand-in 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 become old he says, it needs a ECU. I did a lot of research on them, and found that its a common burden like 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 all sorts of diagnostics on every amalgamated parts (tps, maf, iac). 0-200 all get older I take on it complete the dealer for diagnostics.. upon going problems are in fact count up. I m of two minds to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me tell you a little more very nearly the suffering history. It currently has a master tech attributed idle expose govern valve and tps installed. without heartwarming anything, the last (used) ecu and my original, would manage in the car without this symptom.
subsequent to I begin the car, the engine surges occurring in the middle of 1200 and 2000 rpm support and forth. I untouched the IAC and the TPS like no tweak in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to get used to the idle zeal screw to degrade the rpm and it would retain for a while. Now, the engine is for eternity surging to the dwindling where I cannot drive it for panic of damage to the drive train. Any experienced solution?