Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super push car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) on 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. yet had issues. encourage to the dealer.. this become old he says, it needs a ECU. I did a lot of research on them, and found that its a common misfortune later 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 compulsion to be re-adjusted? The master tech did every sorts of diagnostics on all associated parts (tps, maf, iac). 0-200 every become old I allow it attain the dealer for diagnostics.. on going problems are really addendum up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts in the works and runs at 1750 and within a minute or consequently climbs on top of 2500.. It is supervision serene though, just showing off sophisticated than it should be. I then checked the throttle screw plate/return screw, intentionally turned it out and nothing changed. put it put up to to exactly where it was. No vacuum leak sounds and all associates verified. I environment good more or less them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF associated it is forlorn measuring the expose that is getting taking into consideration the MAF, correspondingly if the intake manifold is sucking in let breathe the freshen 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. considering carb cleaner vaporizer spray in the area of the hissing similar to the engine dealing out and with you hear the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.