Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super spread around car that I am ready to steer off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After aggravating 2-3 rotate used IAC s, I took it to the master tech at lexus. He said it was the IAC valve. He tried my used ones.. and finally a rebuilt one. yet had issues. back up to the dealer.. this epoch he says, it needs a ECU. I did a lot of research upon them, and found that its a common burden once this car.. bought a used one.. more trouble. had the native one rebuilt by a specialist.. and that s where I am at now.. Put it in tonight and the car idles at 2k rpm. Does the TPS obsession to be re-adjusted? The master tech did every sorts of diagnostics on every associated parts (tps, maf, iac). 0-200 every epoch I give a positive response it complete the dealer for diagnostics.. upon going problems are in fact totaling up. I m of two minds to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car occurring this morning, it starts taking place and runs at 1750 and within a minute or so climbs on top of 2500.. It is organization mild though, just habit forward-looking than it should be. I next checked the throttle screw plate/return screw, intentionally turned it out and nothing changed. put it assist to exactly where it was. No vacuum leak sounds and every contacts verified. I character fine more or less them as I've been in there a bunch of times..
as soon as I start the car, the engine surges going on amongst 1200 and 2000 rpm back up and forth. I changed the IAC and the TPS like no fine-tune in symptoms. I have noticed that several Lexus SC's have this thesame issue. Prior to this I would have to adjust the idle enthusiasm screw to lower the rpm and it would support for a while. Now, the engine is constantly surging to the dwindling where I cannot steer it for panic of damage to the drive train. Any experienced solution?