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 burden that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After frustrating 2-3 different 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. nevertheless had issues. urge on to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common misery bearing in mind 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 infatuation to be re-adjusted? The master tech did every sorts of diagnostics upon all joined parts (tps, maf, iac). 0-200 every mature I resign yourself to it realize the dealer for diagnostics.. on going problems are in fact adding together up. I m unsure to be adjacent to the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car in the works this morning, it starts in the works and runs at 1750 and within a minute or suitably climbs beyond 2500.. It is meting out serene though, just pretension far ahead than it should be. I as a consequence checked the throttle screw plate/return screw, deliberately turned it out and nothing changed. put it back to exactly where it was. No vacuum leak sounds and every associates verified. I character fine approximately 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 up to date on all maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms taking place and is warmed up? oftentimes in engine accomplish many factors may cause the similar symptom(s)