Check the hose clips for tightness and examine the trunking for any cracks or splits and plus all the vacuum system, the little bore pipes and fittings for cracks and missing parts. The best showing off to locate a leak is to have the engine admin and warm and after that spray lighter gas /propane or brake cleaner just about each joint in turn. If the engine rev s taking place you ve found your leak.
Thanks for your response. I just checked what you mentioned, that I hadn't already checked, except fuel pressure.Let me say you a tiny more more or less the burden history. It currently has a master tech official idle ventilate run valve and tps installed. without moving anything, the last (used) ecu and my original, would rule in the car without this symptom.
similar to I start the car, the engine surges in the works in the midst of 1200 and 2000 rpm incite and forth. I tainted the IAC and the TPS subsequent to no tweak in symptoms. I have noticed that several Lexus SC's have this same issue. Prior to this I would have to acclimatize the idle speed screw to humiliate the rpm and it would maintain for a while. Now, the engine is for ever and a day surging to the narrowing where I cannot steer it for radio alarm of broken to the drive train. Any experienced solution?