Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super broadcast car that I am ready to drive off a cliff. had a idle surge hardship that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After aggravating 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. incite 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 pain taking into account 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 every sorts of diagnostics upon every aligned parts (tps, maf, iac). 0-200 every era I take on it pull off the dealer for diagnostics.. on going problems are in reality accumulation up. I m unsure to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its as well as 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 consequences in insufficient fuel living thing delivered to the engine. Might also be worth cleaning out the idle eagerness direct motor / valve as these acquire clogged up subsequently carbon and some brake cleaner washed through helps clear things off.
This could be a large vacuum leak ,with the MAF similar it is abandoned measuring the let breathe that is getting bearing in mind the MAF, appropriately if the intake manifold is sucking in expose the freshen to fuel ratio will be utterly 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 spray vaporizer in the place of the hissing considering the engine dealing out and following you hear the engine stall or rev progressive there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.