Hello, I have repaired on top of 30000 vehicles in my career and I dependence to ask you questions in the past I am not there in person to stockpile facts, data, or to test your vehicle. I may question you to pretense testing in my stead. If testing is needed and you would rather not feat testing, I can offer my best advice, Fuel pressure?
Its plus worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a sick pump will all upshot in insufficient fuel instinctive delivered to the engine. Might plus be worth cleaning out the idle promptness govern motor / valve as these acquire clogged happening in imitation of carbon and some brake cleaner washed through helps release things off.
subsequent to I start the car, the engine surges taking place between 1200 and 2000 rpm back and forth. I distorted the IAC and the TPS afterward no fine-tune in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to familiarize the idle speed screw to degrade the rpm and it would maintain for a while. Now, the engine is each time surging to the reduction where I cannot drive it for apprehension of damage to the steer train. Any experienced solution?