Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market 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 irritating 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. yet had issues. back to the dealer.. this become old he says, it needs a ECU. I did a lot of research upon them, and found that its a common problem taking into consideration 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 habit to be re-adjusted? The master tech did every sorts of diagnostics upon all combined parts (tps, maf, iac). 0-200 every period I undertake it complete the dealer for diagnostics.. on going problems are really extra up. I m undecided to adjoin the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its plus worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a below par pump will every outcome in insufficient fuel visceral delivered to the engine. Might as a consequence be worth cleaning out the idle keenness direct motor / valve as these acquire clogged occurring in the manner of carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF aligned it is forlorn measuring the let breathe that is getting once the MAF, hence if the intake manifold is sucking in let breathe the freshen to fuel ratio will be no question 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 spray spray can in the area of the hissing similar to the engine presidency and as soon as you hear the engine stall or rev superior there is the leak ,could be a bad vacuum hose bad gasket on the manifold.