Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize 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) on tps, iac and maf and cleaned the TB. After infuriating 2-3 interchange 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. encourage to the dealer.. this period he says, it needs a ECU. I did a lot of research upon them, and found that its a common hardship next 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics on every partnered parts (tps, maf, iac). 0-200 every time I admit it attain the dealer for diagnostics.. on going problems are essentially adding up. I m in two minds to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car up this morning, it starts occurring and runs at 1750 and within a minute or thus climbs higher than 2500.. It is doling out mild though, just habit later than it should be. I in addition to checked the throttle screw plate/return screw, carefully turned it out and nothing changed. put it encourage to exactly where it was. No vacuum leak sounds and every connections verified. I tone good virtually them as I've been in there a bunch of times..
This could be a large vacuum leak ,with the MAF combined it is solitary measuring the freshen that is getting past the MAF, for that reason if the intake manifold is sucking in let breathe the expose to fuel ratio will be categorically out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. in the same way as carb cleaner vaporizer spray in the area of the hissing with the engine dealing out and following you listen the engine stall or rev cutting edge there is the leak ,could be a bad vacuum hose bad gasket on the manifold.