Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super market car that I am ready to drive off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After exasperating 2-3 interchange 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. 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 pain when 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 obsession to be re-adjusted? The master tech did all sorts of diagnostics on every aligned parts (tps, maf, iac). 0-200 every get older I acknowledge it accomplish the dealer for diagnostics.. on going problems are in fact count up. I m unsure to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
Its then worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel physical delivered to the engine. Might as well as be worth cleaning out the idle swiftness run motor / valve as these get clogged in the works later than carbon and some brake cleaner washed through helps forgive things off.
This could be a large vacuum leak ,with the MAF linked it is and no-one else measuring the air that is getting in the same way as the MAF, for that reason if the intake manifold is sucking in freshen the air 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. subsequently carb cleaner vaporizer spray in the area of the hissing with the engine government and next you hear the engine stall or rev complex there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.