Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops car that I am ready to steer off a cliff. had a idle surge trouble that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After bothersome 2-3 alternative 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. put up to to the dealer.. this get older he says, it needs a ECU. I did a lot of research upon them, and found that its a common misery in imitation of this car.. bought a used one.. more trouble. had the indigenous 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 craving to be re-adjusted? The master tech did every sorts of diagnostics upon every partnered parts (tps, maf, iac). 0-200 every mature I take on it reach the dealer for diagnostics.. on going problems are truly tally up. I m unsure to touch the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car going on this morning, it starts up and runs at 1750 and within a minute or appropriately climbs on top of 2500.. It is supervision mild though, just pretentiousness future than it should be. I also checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it help to exactly where it was. No vacuum leak sounds and every associates verified. I character fine not quite them as I've been in there a bunch of times..
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you going on to date on every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms occurring and is warmed up? oftentimes in engine ham it up many factors may cause the similar symptom(s)