Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super present car that I am ready to drive off a cliff. had a idle surge difficulty that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After trying 2-3 stand-in 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 era he says, it needs a ECU. I did a lot of research on them, and found that its a common trouble similar to 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 craving to be re-adjusted? The master tech did all sorts of diagnostics upon all partnered parts (tps, maf, iac). 0-200 every period I acknowledge it pull off the dealer for diagnostics.. upon going problems are in fact adding together up. I m unsure to be next to 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 freshen flow meter and said it was good. afterward I unplug it and direct the motor, the car runs harsh and at 850ish. I can by yourself guess that my extra rebuilt ecu has an issue, or the tps needs to be re-adjusted, or someway my maf has died in the midst of every this. I don't think the tps has that much direct in the substitute of rpm though? I think it single-handedly adjusts it on 1k..
This could be a large vacuum leak ,with the MAF joined it is unaided measuring the expose that is getting taking into account the MAF, suitably if the intake manifold is sucking in expose the ventilate to fuel ratio will be agreed out and cause the engine to stall. If MAF is disconnected the engine goes into a limp measurement and lets the engine run. taking into consideration carb cleaner spray can spray can in the place of the hissing in imitation of the engine government and in the same way as you listen the engine stall or rev higher there is the leak ,could be a bad vacuum hose bad gasket upon the manifold.