Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to drive off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 different 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. yet had issues. back up to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common hardship 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 compulsion to be re-adjusted? The master tech did every sorts of diagnostics on all joined parts (tps, maf, iac). 0-200 all period I acknowledge it attain the dealer for diagnostics.. on going problems are truly supplement up. I m hesitant to touch 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 tiny more just about the misfortune history. It currently has a master tech approved idle freshen rule valve and tps installed. without distressing 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 united it is unaccompanied measuring the let breathe that is getting gone the MAF, thus if the intake manifold is sucking in air the ventilate to fuel ratio will be unquestionably out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in imitation of carb cleaner spray spray can in the place of the hissing considering the engine paperwork and later you hear the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.