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) upon tps, iac and maf and cleaned the TB. After exasperating 2-3 different 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 times he says, it needs a ECU. I did a lot of research upon them, and found that its a common problem subsequent to 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics upon all related parts (tps, maf, iac). 0-200 every time I take it accomplish the dealer for diagnostics.. on going problems are in fact adding together 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 freshen flow meter and said it was good. as soon as I unplug it and control the motor, the car runs unfriendly and at 850ish. I can without help guess that my further rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of every this. I don't think the tps has that much govern in the every second of rpm though? I think it without help adjusts it vis--vis 1k..
This could be a large vacuum leak ,with the MAF linked it is unaided measuring the air that is getting when the MAF, for that reason if the intake manifold is sucking in freshen the air to fuel ratio will be totally out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. next carb cleaner spray spray can in the place of the hissing following the engine processing and following you hear the engine stall or rev sophisticated there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.