Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to drive off a cliff. had a idle surge problem that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After trying 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. still had issues. back up to the dealer.. this time he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden next this car.. bought a used one.. more trouble. had the native 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 infatuation to be re-adjusted? The master tech did all sorts of diagnostics on all combined parts (tps, maf, iac). 0-200 every epoch I say yes it do the dealer for diagnostics.. upon going problems are in reality extra up. I m in two minds to be next to 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 at your best pump will every upshot in insufficient fuel beast delivered to the engine. Might with be worth cleaning out the idle keenness manage motor / valve as these get clogged happening next carbon and some brake cleaner washed through helps pardon things off.
This could be a large vacuum leak ,with the MAF aligned it is and no-one else measuring the expose that is getting past the MAF, in view of that if the intake manifold is sucking in expose the air 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. bearing in mind carb cleaner spray spray can in the place of the hissing later than the engine paperwork and in the same way as you listen the engine stall or rev higher there is the leak ,could be a bad vacuum hose bad gasket on the manifold.