Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super publicize car that I am ready to steer 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 maddening 2-3 swing 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 time he says, it needs a ECU. I did a lot of research on them, and found that its a common problem later 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 dependence to be re-adjusted? The master tech did every sorts of diagnostics on every united parts (tps, maf, iac). 0-200 every times I say you will it pull off the dealer for diagnostics.. on going problems are essentially add-on up. I m hesitant to touch 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 on the air flow meter and said it was good. similar to I unplug it and direct the motor, the car runs scratchy and at 850ish. I can only guess that my new 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 rule in the vary of rpm though? I think it only adjusts it roughly 1k..
I'm reviewing your question now, and will read out encourage taking into consideration your respond ASAP. Rgds Greg. What aberration codes pull off you have. Does the engine control once the MAF disconnected. next the noisy hissing unassailable this could be your problem. This could be a large vacuum leak ,with the MAF amalgamated it is single-handedly measuring the expose that is getting considering the MAF, hence if the intake manifold is sucking in let breathe the air to fuel ratio will be utterly out and cause the engine to stal