Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market car that I am ready to steer off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After grating 2-3 substitute 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. put up to to the dealer.. this grow old he says, it needs a ECU. I did a lot of research on them, and found that its a common suffering when 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 every partnered parts (tps, maf, iac). 0-200 all become old I allow it reach the dealer for diagnostics.. upon going problems are in reality totaling up. I m undecided 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 say you a little more not quite the trouble history. It currently has a master tech ascribed idle ventilate direct valve and tps installed. without upsetting anything, the last (used) ecu and my original, would govern in the car without this symptom.
I'm reviewing your question now, and will pronounce back when your respond ASAP. Rgds Greg. What malfunction codes attain you have. Does the engine manage subsequent to the MAF disconnected. considering the noisy hissing unquestionable this could be your problem. This could be a large vacuum leak ,with the MAF linked it is by yourself measuring the ventilate that is getting later the MAF, fittingly if the intake manifold is sucking in expose the ventilate to fuel ratio will be completely out and cause the engine to stal