Check the hose clips for tightness and inspect the trunking for any cracks or splits and next all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best artifice to locate a leak is to have the engine processing and warm and subsequently spray can lighter gas /propane or brake cleaner just about each joint in turn. If the engine rev s in the works you ve found your leak.
I started the car stirring this morning, it starts going on and runs at 1750 and within a minute or fittingly climbs higher than 2500.. It is presidency smooth though, just pretension vanguard than it should be. I also checked the throttle screw plate/return screw, on purpose turned it out and nothing changed. put it assist to exactly where it was. No vacuum leak sounds and every connections verified. I tone fine virtually them as I've been in there a bunch of times..
following I start the car, the engine surges taking place surrounded by 1200 and 2000 rpm assist and forth. I tainted the IAC and the TPS bearing in mind no modify in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to get used to the idle readiness screw to humiliate the rpm and it would maintain for a while. Now, the engine is for ever and a day surging to the tapering off where I cannot steer it for danger signal of damage to the drive train. Any experienced solution?