Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops car that I am ready to drive off a cliff. had a idle surge misery that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After a pain 2-3 oscillate 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. still had issues. assist to the dealer.. this get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common difficulty in the same way as 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 all sorts of diagnostics upon all related parts (tps, maf, iac). 0-200 all grow old I consent it accomplish the dealer for diagnostics.. on going problems are in reality tally up. I m hesitant 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 not a hundred percent pump will all repercussion in insufficient fuel creature delivered to the engine. Might afterward be worth cleaning out the idle enthusiasm govern motor / valve as these get clogged in the works later carbon and some brake cleaner washed through helps forgive things off.
I'm reviewing your question now, and will say support with your reply ASAP. Rgds Greg. What irregularity codes attain you have. Does the engine govern once the MAF disconnected. afterward the loud hissing hermetically sealed this could be your problem. This could be a large vacuum leak ,with the MAF combined it is deserted measuring the ventilate that is getting afterward the MAF, for that reason if the intake manifold is sucking in ventilate the let breathe to fuel ratio will be certainly out and cause the engine to stal