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 hardship that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 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. nevertheless had issues. assist to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common pain with 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 habit to be re-adjusted? The master tech did all sorts of diagnostics upon every aligned parts (tps, maf, iac). 0-200 every mature I recognize it pull off the dealer for diagnostics.. on going problems are in reality add-on up. I m undecided 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 tiny more just about the misfortune history. It currently has a master tech official idle freshen manage valve and tps installed. without touching anything, the last (used) ecu and my original, would run in the car without this symptom.
This could be a large vacuum leak ,with the MAF associated it is abandoned measuring the expose that is getting similar to the MAF, suitably if the intake manifold is sucking in ventilate the ventilate to fuel ratio will be completely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. when carb cleaner spray can vaporizer in the area of the hissing gone the engine organization and considering you listen the engine stall or rev complex there is the leak ,could be a bad vacuum hose bad gasket on the manifold.