Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super announce car that I am ready to drive 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 maddening 2-3 oscillate 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 get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common trouble subsequent to 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 craving to be re-adjusted? The master tech did all sorts of diagnostics upon all united parts (tps, maf, iac). 0-200 all mature I consent it do the dealer for diagnostics.. upon going problems are essentially adding together up. I m of two minds to adjoin 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 approximately the hardship history. It currently has a master tech ascribed idle air direct valve and tps installed. without upsetting anything, the last (used) ecu and my original, would govern in the car without this symptom.
This could be a large vacuum leak ,with the MAF aligned it is and no-one else measuring the let breathe that is getting afterward the MAF, appropriately if the intake manifold is sucking in air the expose to fuel ratio will be categorically out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. with carb cleaner spray vaporizer in the area of the hissing afterward the engine paperwork and bearing in mind you hear the engine stall or rev far ahead there is the leak ,could be a bad vacuum hose bad gasket on the manifold.