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 misfortune that I researched online and did tests (per the manual) on tps, iac and maf and cleaned the TB. After exasperating 2-3 substitute 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. help to the dealer.. this epoch he says, it needs a ECU. I did a lot of research on them, and found that its a common difficulty taking into consideration 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 all sorts of diagnostics upon all partnered parts (tps, maf, iac). 0-200 every get older I take it reach the dealer for diagnostics.. upon going problems are in reality accumulation up. I m unsure to adjoin 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 air flow meter and said it was good. following I unplug it and direct the motor, the car runs sharp and at 850ish. I can unaided 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 all this. I don't think the tps has that much rule in the oscillate of rpm though? I think it isolated adjusts it roughly speaking 1k..
I'm reviewing your question now, and will publish encourage later your reply ASAP. Rgds Greg. What oddity codes realize you have. Does the engine rule behind the MAF disconnected. later than the noisy hissing unassailable this could be your problem. This could be a large vacuum leak ,with the MAF combined it is abandoned measuring the freshen that is getting next the MAF, so if the intake manifold is sucking in freshen the let breathe to fuel ratio will be unconditionally out and cause the engine to stal