Hi, this car is kicking everyone s ass.. 92 lexus sc400. 128k. Super puff car that I am ready to steer off a cliff. had a idle surge suffering that I researched online and did tests (per the manual) upon tps, iac and maf and cleaned the TB. After bothersome 2-3 oscillate 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. urge on to the dealer.. this era he says, it needs a ECU. I did a lot of research upon them, and found that its a common pain with this car.. bought a used one.. more trouble. had the indigenous 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 compulsion to be re-adjusted? The master tech did every sorts of diagnostics on all related parts (tps, maf, iac). 0-200 every era I take it reach the dealer for diagnostics.. on going problems are in point of fact accumulation up. I m in two minds to be next to the tps if he had it dialed. Any insight? Thanks in advance. Jason
Might then be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick deformity find if you unplug the meter and rule the engine without it. if the engine condition is the thesame later chances are the meter or the attachment to it is faulty. Its furthermore worth cleaning the MAF sensor wires, as they can get coated later dirt exceeding time which subsequently offsets the reading. Use some admittance cleaner or brake cleaner to spray onto the wires to separate the dirt upon no account adjoin the wires following all as they are enormously fragile
considering I begin the car, the engine surges going on in the company of 1200 and 2000 rpm help and forth. I tainted the IAC and the TPS subsequent to no fine-tune in symptoms. I have noticed that several Lexus SC's have this similar issue. Prior to this I would have to adjust the idle quickness screw to lower the rpm and it would withhold for a while. Now, the engine is until the end of time surging to the narrowing where I cannot drive it for panic of broken to the drive train. Any experienced solution?