Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to drive off a cliff. had a idle surge misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 2-3 every other 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. still had issues. incite to the dealer.. this mature he says, it needs a ECU. I did a lot of research on them, and found that its a common difficulty behind this car.. bought a used one.. more trouble. had the original 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 dependence to be re-adjusted? The master tech did all sorts of diagnostics on every linked parts (tps, maf, iac). 0-200 every grow old I say yes it get the dealer for diagnostics.. on going problems are essentially extra up. I m unsure to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
I started the car in the works this morning, it starts occurring and runs at 1750 and within a minute or for that reason climbs beyond 2500.. It is organization smooth though, just pretentiousness superior than it should be. I then checked the throttle screw plate/return screw, with intent turned it out and nothing changed. put it put up to to exactly where it was. No vacuum leak sounds and every associates verified. I character fine nearly 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 upon every maintenance; spark plugs fuel filter pcv vlave etc? have you performed a visual inspection and listened to engine as it warms going on and is warmed up? oftentimes in engine action many factors may cause the similar symptom(s)