Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super promote car that I am ready to steer 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 different 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. back up to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common pain like this car.. bought a used one.. more trouble. had the indigenous 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 on every joined parts (tps, maf, iac). 0-200 every time I take it realize the dealer for diagnostics.. on going problems are in fact supplement up. I m unsure to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its afterward worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a sick pump will all upshot in insufficient fuel brute delivered to the engine. Might moreover be worth cleaning out the idle eagerness control motor / valve as these get clogged taking place in the same way as carbon and some brake cleaner washed through helps clear things off.
This could be a large vacuum leak ,with the MAF united it is lonesome measuring the freshen that is getting subsequent to the MAF, thus if the intake manifold is sucking in ventilate the ventilate to fuel ratio will be totally out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. following carb cleaner spray can spray in the place of the hissing next the engine supervision and in the manner of you hear the engine stall or rev progressive there is the leak ,could be a bad vacuum hose bad gasket on the manifold.