Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast 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 frustrating 2-3 alternative 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. incite to the dealer.. this get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common hardship similar to 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 dependence to be re-adjusted? The master tech did all sorts of diagnostics on every related parts (tps, maf, iac). 0-200 every epoch I acknowledge it reach the dealer for diagnostics.. on going problems are in fact adding up up. I m hesitant 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 say you a little more more or less the suffering history. It currently has a master tech ascribed idle let breathe govern valve and tps installed. without heartwarming anything, the last (used) ecu and my original, would manage in the car without this symptom.
I'm reviewing your question now, and will read out assist when your reply ASAP. Rgds Greg. What anomaly codes get you have. Does the engine govern similar to the MAF disconnected. following the loud hissing hermetically sealed this could be your problem. This could be a large vacuum leak ,with the MAF connected it is single-handedly measuring the expose that is getting later than the MAF, fittingly if the intake manifold is sucking in expose the air to fuel ratio will be totally out and cause the engine to stal