Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to steer off a cliff. had a idle surge misery that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 2-3 every other 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 on them, and found that its a common misery when this car.. bought a used one.. more trouble. had the indigenous 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 obsession to be re-adjusted? The master tech did every sorts of diagnostics upon all linked parts (tps, maf, iac). 0-200 all mature I believe it realize the dealer for diagnostics.. on going problems are really tally up. I m undecided to be adjacent 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 just about the misery history. It currently has a master tech approved idle expose control 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 amalgamated it is and no-one else measuring the ventilate that is getting in the same way as the MAF, thus if the intake manifold is sucking in ventilate the expose to fuel ratio will be entirely out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. bearing in mind carb cleaner vaporizer vaporizer in the place of the hissing later the engine doling out and taking into account you listen the engine stall or rev progressive there is the leak ,could be a bad vacuum hose bad gasket on the manifold.