Check the hose clips for tightness and examine the trunking for any cracks or splits and in addition to all the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best habit to locate a leak is to have the engine organization and hot and next spray lighter gas /propane or brake cleaner almost each joint in turn. If the engine rev s in the works you ve found your leak.
Its with 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 all outcome in insufficient fuel creature delivered to the engine. Might with be worth cleaning out the idle eagerness manage motor / valve as these acquire clogged in the works when carbon and some brake cleaner washed through helps clear things off.
afterward I begin the car, the engine surges in the works amongst 1200 and 2000 rpm help and forth. I changed the IAC and the TPS past no regulate in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to become accustomed the idle enthusiasm screw to demean the rpm and it would keep for a while. Now, the engine is forever surging to the narrowing where I cannot steer it for agitation of damage to the drive train. Any experienced solution?