Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super shout from the rooftops car that I am ready to drive off a cliff. had a idle surge pain that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After grating 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. still had issues. assist to the dealer.. this era he says, it needs a ECU. I did a lot of research on them, and found that its a common misery subsequently 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 need to be re-adjusted? The master tech did every sorts of diagnostics upon every associated parts (tps, maf, iac). 0-200 every period I endure it get the dealer for diagnostics.. on going problems are truly totaling up. I m in two minds to lie alongside the tps if he had it dialed. Any insight? Thanks in advance. Jason
I did re-check them tho. The master tech did extensive tests upon the expose flow meter and said it was good. subsequent to I unplug it and govern the motor, the car runs brusque and at 850ish. I can lonesome guess that my other rebuilt ecu has an issue, or the tps needs to be re-adjusted, or anyhow my maf has died in the midst of every this. I don't think the tps has that much run in the different of rpm though? I think it without help adjusts it not far off from 1k..
have you looked into throttle body coking and/or combustion chamber/valve carbon buildup? are you taking place to date upon all 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 feint many factors may cause the similar symptom(s)