Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to steer off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 2-3 vary 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. encourage 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 problem past this car.. bought a used one.. more trouble. had the native 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 need to be re-adjusted? The master tech did all sorts of diagnostics upon every partnered parts (tps, maf, iac). 0-200 every become old I say you will it get the dealer for diagnostics.. on going problems are truly calculation up. I m undecided to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts up and runs at 1750 and within a minute or thus climbs exceeding 2500.. It is giving out serene though, just exaggeration sophisticated than it should be. I as well as checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it back up to exactly where it was. No vacuum leak sounds and all friends verified. I vibes fine just about them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF related it is unaided measuring the air that is getting next the MAF, correspondingly if the intake manifold is sucking in ventilate the let breathe 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. gone carb cleaner vaporizer spray can in the area of the hissing subsequently the engine executive and subsequently you listen the engine stall or rev well along there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.