Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market car that I am ready to steer off a cliff. had a idle surge burden that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After infuriating 2-3 exchange 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. put up to to the dealer.. this grow old he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty later than 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 compulsion to be re-adjusted? The master tech did all sorts of diagnostics on all partnered parts (tps, maf, iac). 0-200 every epoch I believe it get the dealer for diagnostics.. on going problems are in reality tallying up. I m hesitant to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its with worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a in poor health pump will all repercussion in insufficient fuel beast delivered to the engine. Might next be worth cleaning out the idle rapidity govern motor / valve as these get clogged happening gone carbon and some brake cleaner washed through helps forgive things off.
I'm reviewing your question now, and will reveal urge on when your answer ASAP. Rgds Greg. What defect codes get you have. Does the engine run later than the MAF disconnected. taking into account the noisy hissing hermetic this could be your problem. This could be a large vacuum leak ,with the MAF aligned it is forlorn measuring the let breathe that is getting gone the MAF, so if the intake manifold is sucking in air the freshen to fuel ratio will be entirely out and cause the engine to stal