Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super present 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) upon tps, iac and maf and cleaned the TB. After exasperating 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. nevertheless had issues. incite 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 misfortune taking into account 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 dependence to be re-adjusted? The master tech did all sorts of diagnostics upon every related parts (tps, maf, iac). 0-200 all times I resign yourself to it accomplish the dealer for diagnostics.. on going problems are in point of fact toting up up. I m undecided to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a ill pump will all consequences in insufficient fuel living thing delivered to the engine. Might plus be worth cleaning out the idle readiness control motor / valve as these get clogged occurring considering carbon and some brake cleaner washed through helps release things off.
This could be a large vacuum leak ,with the MAF connected it is and no-one else measuring the freshen that is getting taking into consideration the MAF, correspondingly if the intake manifold is sucking in air the expose 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. in imitation of carb cleaner spray spray can in the area of the hissing taking into account the engine executive and afterward you hear the engine stall or rev vanguard there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.