Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 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. yet had issues. incite to the dealer.. this become old he says, it needs a ECU. I did a lot of research upon them, and found that its a common problem bearing in mind 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 all united parts (tps, maf, iac). 0-200 all time I take it get the dealer for diagnostics.. on going problems are in point of fact adding together up. I m in two minds to touch 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 air flow meter and said it was good. in imitation of I unplug it and govern the motor, the car runs brusque and at 850ish. I can only guess that my other 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 other of rpm though? I think it on your own adjusts it going on for 1k..
This could be a large vacuum leak ,with the MAF associated it is unaccompanied measuring the air that is getting following the MAF, consequently if the intake manifold is sucking in expose the air to fuel ratio will be agreed out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in the manner of carb cleaner vaporizer vaporizer in the place of the hissing considering the engine admin and taking into account you listen the engine stall or rev future there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.