Check the hose clips for tightness and inspect the trunking for any cracks or splits and as a consequence every the vacuum system, the small bore pipes and fittings for cracks and missing parts. The best artifice to locate a leak is to have the engine giving out and warm and next spray lighter gas /propane or brake cleaner a propos each joint in turn. If the engine rev s up 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 tell you a tiny more just about the trouble history. It currently has a master tech official idle freshen run valve and tps installed. without distressing anything, the last (used) ecu and my original, would control in the car without this symptom.
later than I start the car, the engine surges going on in the midst of 1200 and 2000 rpm put up to and forth. I misused the IAC and the TPS as soon as no fiddle with in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to acclimatize the idle zeal screw to demean the rpm and it would preserve for a while. Now, the engine is continuously surging to the narrowing where I cannot drive it for scare of broken to the steer train. Any experienced solution?