Hello, I have repaired greater than 30000 vehicles in my career and I obsession to ask you questions in the past I am not there in person to accrue facts, data, or to test your vehicle. I may ask you to be in testing in my stead. If chemical analysis is needed and you would rather not operate testing, I can meet the expense of my best advice, Fuel pressure?
Its moreover worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a below par pump will every outcome in insufficient fuel beast delivered to the engine. Might next be worth cleaning out the idle swiftness manage motor / valve as these acquire clogged up following carbon and some brake cleaner washed through helps clear things off.
bearing in mind I start the car, the engine surges taking place between 1200 and 2000 rpm put up to and forth. I misused the IAC and the TPS taking into account no fine-tune in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to adapt the idle speed screw to degrade the rpm and it would hold for a while. Now, the engine is all the time surging to the lessening where I cannot steer it for bell of damage to the drive train. Any experienced solution?