Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super make public car that I am ready to drive off a cliff. had a idle surge problem that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After irritating 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. assist to the dealer.. this times he says, it needs a ECU. I did a lot of research on them, and found that its a common pain later 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 every joined parts (tps, maf, iac). 0-200 every epoch I agree to it accomplish the dealer for diagnostics.. on going problems are essentially accumulation up. I m of two minds 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 upon the expose flow meter and said it was good. taking into consideration I unplug it and rule the motor, the car runs rude and at 850ish. I can without help 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 all this. I don't think the tps has that much run in the interchange of rpm though? I think it isolated adjusts it roughly speaking 1k..
This could be a large vacuum leak ,with the MAF united it is without help measuring the let breathe that is getting gone the MAF, correspondingly if the intake manifold is sucking in ventilate the air to fuel ratio will be utterly out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. afterward carb cleaner spray vaporizer in the place of the hissing with the engine direction and considering you listen the engine stall or rev difficult there is the leak ,could be a bad vacuum hose bad gasket on the manifold.