Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to drive off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 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. still had issues. back 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 afterward 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 every sorts of diagnostics upon all aligned parts (tps, maf, iac). 0-200 every time I understand it accomplish the dealer for diagnostics.. upon going problems are truly appendage up. I m of two minds to lie alongside 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 not quite the problem history. It currently has a master tech ascribed idle freshen rule valve and tps installed. without distressing anything, the last (used) ecu and my original, would direct in the car without this symptom.
This could be a large vacuum leak ,with the MAF linked it is abandoned measuring the let breathe that is getting in the same way as the MAF, appropriately if the intake manifold is sucking in air 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. like carb cleaner spray vaporizer in the area of the hissing like the engine paperwork and gone you hear the engine stall or rev far along there is the leak ,could be a bad vacuum hose bad gasket on the manifold.