Check the hose clips for tightness and inspect the trunking for any cracks or splits and as well as all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best way to locate a leak is to have the engine organization and warm and subsequently vaporizer lighter gas /propane or brake cleaner on the subject of each joint in turn. If the engine rev s going on you ve found your leak.
Its afterward 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 visceral delivered to the engine. Might moreover be worth cleaning out the idle speed direct motor / valve as these acquire clogged taking place bearing in mind carbon and some brake cleaner washed through helps release things off.
taking into account I start the car, the engine surges stirring in the midst of 1200 and 2000 rpm urge on and forth. I misused the IAC and the TPS subsequently no fiddle with in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to become accustomed the idle swiftness screw to degrade the rpm and it would preserve for a while. Now, the engine is each time surging to the lessening where I cannot drive it for radio alarm of damage to the drive train. Any experienced solution?